

<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilities" xlink:href="flks-20170331.xsd#AccruedExpensesAndOtherCurrentLiabilities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:href="flks-20170331.xsd#AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:href="flks-20170331.xsd#AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecurities" xlink:href="flks-20170331.xsd#CashEquivalentsAndMarketableSecurities" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecuritiesDetails" xlink:href="flks-20170331.xsd#CashEquivalentsAndMarketableSecuritiesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecuritiesTables" xlink:href="flks-20170331.xsd#CashEquivalentsAndMarketableSecuritiesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CommonStock" xlink:href="flks-20170331.xsd#CommonStock" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CommonStockNarrativeDetails" xlink:href="flks-20170331.xsd#CommonStockNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CommonStockRestrictedCommonStockActivityDetails" xlink:href="flks-20170331.xsd#CommonStockRestrictedCommonStockActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CommonStockTables" xlink:href="flks-20170331.xsd#CommonStockTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CondensedConsolidatedBalanceSheetsUnaudited" xlink:href="flks-20170331.xsd#CondensedConsolidatedBalanceSheetsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical" xlink:href="flks-20170331.xsd#CondensedConsolidatedBalanceSheetsUnauditedParenthetical" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited" xlink:href="flks-20170331.xsd#CondensedConsolidatedStatementsOfCashFlowsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfComprehensiveLossUnaudited" xlink:href="flks-20170331.xsd#CondensedConsolidatedStatementsOfComprehensiveLossUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited" xlink:href="flks-20170331.xsd#CondensedConsolidatedStatementsOfOperationsUnaudited" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/DocumentAndEntityInformation" xlink:href="flks-20170331.xsd#DocumentAndEntityInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/FairValueMeasurements" xlink:href="flks-20170331.xsd#FairValueMeasurements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/FairValueMeasurementsDetails" xlink:href="flks-20170331.xsd#FairValueMeasurementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/FairValueMeasurementsTables" xlink:href="flks-20170331.xsd#FairValueMeasurementsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/IncomeTaxes" xlink:href="flks-20170331.xsd#IncomeTaxes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/IncomeTaxesDetails" xlink:href="flks-20170331.xsd#IncomeTaxesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/Inventory" xlink:href="flks-20170331.xsd#Inventory" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/InventoryDetails" xlink:href="flks-20170331.xsd#InventoryDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/InventoryTables" xlink:href="flks-20170331.xsd#InventoryTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/NetLossPerShare" xlink:href="flks-20170331.xsd#NetLossPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/NetLossPerShareDetails" xlink:href="flks-20170331.xsd#NetLossPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/NetLossPerShareTables" xlink:href="flks-20170331.xsd#NetLossPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/OrganizationAndOperations" xlink:href="flks-20170331.xsd#OrganizationAndOperations" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/OrganizationAndOperationsDetails" xlink:href="flks-20170331.xsd#OrganizationAndOperationsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SegmentInformation" xlink:href="flks-20170331.xsd#SegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SegmentInformationDetails" xlink:href="flks-20170331.xsd#SegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SegmentInformationTables" xlink:href="flks-20170331.xsd#SegmentInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/StockBasedCompensation" xlink:href="flks-20170331.xsd#StockBasedCompensation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/StockBasedCompensationNarrativeDetails" xlink:href="flks-20170331.xsd#StockBasedCompensationNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/StockBasedCompensationSummaryOfStockBasedCompensationExpenseDetails" xlink:href="flks-20170331.xsd#StockBasedCompensationSummaryOfStockBasedCompensationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/StockBasedCompensationSummaryOfStockOptionActivityDetails" xlink:href="flks-20170331.xsd#StockBasedCompensationSummaryOfStockOptionActivityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/StockBasedCompensationTables" xlink:href="flks-20170331.xsd#StockBasedCompensationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements" xlink:href="flks-20170331.xsd#SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNarrativeDetails" xlink:href="flks-20170331.xsd#SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:href="flks-20170331.xsd#SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedNetLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedNetLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodEndLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodEndLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedPeriodStartLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedPeriodStartLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTerseLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:href="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd#negatedTotalLabel" xlink:type="simple" />
  <link:roleRef roleURI="http://www.xbrl.org/2009/role/netLabel" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" xlink:type="simple" />
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilities" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="loc_us-gaap_PayablesAndAccrualsAbstract_2845E7E1AE7451869BCADF95116FCABA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock" xlink:label="loc_us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_EE455596E8025619B81E20DEC4AABA2F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_2845E7E1AE7451869BCADF95116FCABA" xlink:to="loc_us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_EE455596E8025619B81E20DEC4AABA2F" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilitiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:type="locator" />
    <link:loc xlink:href="flks-20170331.xsd#flks_AccruedResearchAndDevelopmentExpenseCurrent" xlink:label="loc_flks_AccruedResearchAndDevelopmentExpenseCurrent_9FC1CC3BD55DA809C74391DC47B3A402" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:to="loc_flks_AccruedResearchAndDevelopmentExpenseCurrent_9FC1CC3BD55DA809C74391DC47B3A402" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_2DD71CF37724072B45D891DC47B32B60" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_2DD71CF37724072B45D891DC47B32B60" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:label="loc_us-gaap_AccruedProfessionalFeesCurrent_A78B4CD815F0C43A008391DC47B3029B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:to="loc_us-gaap_AccruedProfessionalFeesCurrent_A78B4CD815F0C43A008391DC47B3029B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedMarketingCostsCurrent" xlink:label="loc_us-gaap_AccruedMarketingCostsCurrent_9B0B1D69A2DD327563DA91DC47B37036" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:to="loc_us-gaap_AccruedMarketingCostsCurrent_9B0B1D69A2DD327563DA91DC47B37036" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_AccruedExpensesAndOtherCurrentLiabilities" xlink:label="loc_flks_AccruedExpensesAndOtherCurrentLiabilities_507EBF5C7BF2B8E5E96291DC47B33019" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_544136D57FFF166B2C8E91DC47B3D0FC" xlink:to="loc_flks_AccruedExpensesAndOtherCurrentLiabilities_507EBF5C7BF2B8E5E96291DC47B33019" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/AccruedExpensesAndOtherCurrentLiabilitiesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PayablesAndAccrualsAbstract" xlink:label="loc_us-gaap_PayablesAndAccrualsAbstract_B597B4F05961525ABDA70348B358F89D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock_A69AAAADEF4C505DA2C202D617D2E1FB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_B597B4F05961525ABDA70348B358F89D" xlink:to="loc_us-gaap_ScheduleOfAccruedLiabilitiesTableTextBlock_A69AAAADEF4C505DA2C202D617D2E1FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherCurrentLiabilitiesTableTextBlock" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesTableTextBlock_F2230CFD89355DB9B61AE468AC3B59E5" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PayablesAndAccrualsAbstract_B597B4F05961525ABDA70348B358F89D" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesTableTextBlock_F2230CFD89355DB9B61AE468AC3B59E5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecurities" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="loc_us-gaap_CashAndCashEquivalentsAbstract_DDE836B51F115764B0E2CC5112EC836B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock" xlink:label="loc_us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock_997E924985705C6DB74569FE9B719558" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashAndCashEquivalentsAbstract_DDE836B51F115764B0E2CC5112EC836B" xlink:to="loc_us-gaap_CashCashEquivalentsAndMarketableSecuritiesTextBlock_997E924985705C6DB74569FE9B719558" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="loc_us-gaap_CashAndCashEquivalentsAbstract_BB3BC3583EC1C4F35D9DCA51BB28EC9C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1C45FE7041B44BCF4480CA51BB285670" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashAndCashEquivalentsAbstract_BB3BC3583EC1C4F35D9DCA51BB28EC9C" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1C45FE7041B44BCF4480CA51BB285670" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_229046911C10F9ED1DDDCA51BB28644C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1C45FE7041B44BCF4480CA51BB285670" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_229046911C10F9ED1DDDCA51BB28644C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_E0558B78BBD4E83B62F0CA51BB28CB7E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_229046911C10F9ED1DDDCA51BB28644C" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_E0558B78BBD4E83B62F0CA51BB28CB7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_4C8B6925482A5A4EAB0FCA51BB28F127" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_E0558B78BBD4E83B62F0CA51BB28CB7E" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_4C8B6925482A5A4EAB0FCA51BB28F127" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_A7510809CBDDB056A61DCA51BB28E504" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_E0558B78BBD4E83B62F0CA51BB28CB7E" xlink:to="loc_us-gaap_CommercialPaperMember_A7510809CBDDB056A61DCA51BB28E504" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_092679CE29B698835F3ECA51BB282EDF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_E0558B78BBD4E83B62F0CA51BB28CB7E" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_092679CE29B698835F3ECA51BB282EDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_1C45FE7041B44BCF4480CA51BB285670" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAmortizedCost" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_85941322FAFCA7E41F0ACA51BB28617C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAmortizedCost_85941322FAFCA7E41F0ACA51BB28617C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_FFACF7DCBA5B3A0B7DFACA51BB28C47E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_FFACF7DCBA5B3A0B7DFACA51BB28C47E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_C00236B9CE72A3FEAB23CA51BB299499" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_C00236B9CE72A3FEAB23CA51BB299499" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_0CD146354756C954400BCA51BB29D069" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableForSaleSecurities_0CD146354756C954400BCA51BB29D069" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1" xlink:label="loc_us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1_F4CA67A1AA5C0A77AAB1CA51BB291E09" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1_F4CA67A1AA5C0A77AAB1CA51BB291E09" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_DB6945F9F17B0D6F750ECA51BB290353" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_A81110AA16BC7FE8D452CA51BB28A06F" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue_DB6945F9F17B0D6F750ECA51BB290353" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CashEquivalentsAndMarketableSecuritiesTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAbstract" xlink:label="loc_us-gaap_CashAndCashEquivalentsAbstract_0B2845E58A9D59EDA1499910D8CB029E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecuritiesTextBlock" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesTextBlock_B50658AF82EB5D1A9C1DA7D3CD443CF7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_CashAndCashEquivalentsAbstract_0B2845E58A9D59EDA1499910D8CB029E" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesTextBlock_B50658AF82EB5D1A9C1DA7D3CD443CF7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CommonStock" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract_5AE4CF53423F5881851F9C5D753092DB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:label="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock_53C067648E4653C3BC393554ADDBED48" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityAbstract_5AE4CF53423F5881851F9C5D753092DB" xlink:to="loc_us-gaap_StockholdersEquityNoteDisclosureTextBlock_53C067648E4653C3BC393554ADDBED48" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CommonStockNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract_4E5EFF7B42875798B15F5885A8416AE5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityAbstract_4E5EFF7B42875798B15F5885A8416AE5" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_7EF1DE92D3FF5C00A05E5ADCEBCE460F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:to="loc_us-gaap_AwardTypeAxis_7EF1DE92D3FF5C00A05E5ADCEBCE460F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8B27A5993C065BEE8D1E3E970BCF3BCF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_7EF1DE92D3FF5C00A05E5ADCEBCE460F" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8B27A5993C065BEE8D1E3E970BCF3BCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_19FE98E381615D76B1BC03186317D7CC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8B27A5993C065BEE8D1E3E970BCF3BCF" xlink:to="loc_us-gaap_RestrictedStockMember_19FE98E381615D76B1BC03186317D7CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VestingAxis" xlink:label="loc_us-gaap_VestingAxis_AB135537C896555EB9BF6443A3C3D8CA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:to="loc_us-gaap_VestingAxis_AB135537C896555EB9BF6443A3C3D8CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_VestingDomain" xlink:label="loc_us-gaap_VestingDomain_78B5CB808EB95913BDB2CF5FBAC4B7F6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_VestingAxis_AB135537C896555EB9BF6443A3C3D8CA" xlink:to="loc_us-gaap_VestingDomain_78B5CB808EB95913BDB2CF5FBAC4B7F6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_6375DBC4BD6B5C45A64FC3799D7B3E22" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_VestingDomain_78B5CB808EB95913BDB2CF5FBAC4B7F6" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_6375DBC4BD6B5C45A64FC3799D7B3E22" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_9C96A18443EA59A4BE6D89FF78A4698A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_VestingDomain_78B5CB808EB95913BDB2CF5FBAC4B7F6" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_9C96A18443EA59A4BE6D89FF78A4698A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_54D41D419C085F0B9077CF6A23E23E61" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:to="loc_us-gaap_TitleOfIndividualAxis_54D41D419C085F0B9077CF6A23E23E61" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4E460FBC95765FAB8BBAC9C9715C7B39" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualAxis_54D41D419C085F0B9077CF6A23E23E61" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4E460FBC95765FAB8BBAC9C9715C7B39" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_NonemployeeConsultantsandAdvisersMember" xlink:label="loc_flks_NonemployeeConsultantsandAdvisersMember_F2E9CC7EC3225F3192975B7F9C4FBCEF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_4E460FBC95765FAB8BBAC9C9715C7B39" xlink:to="loc_flks_NonemployeeConsultantsandAdvisersMember_F2E9CC7EC3225F3192975B7F9C4FBCEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_38944719E306502E9AC93D661F83EFE6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_BA566CEE79CC5A1B9666D7405621DB92" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_BA566CEE79CC5A1B9666D7405621DB92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_90B17A08F78952C4A068D88B87A02C9D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_90B17A08F78952C4A068D88B87A02C9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_D3C3AACBC7C5556486E762E3415B6798" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_D3C3AACBC7C5556486E762E3415B6798" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_F05B91C339E755609DA7AAD77EB3A93C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_F05B91C339E755609DA7AAD77EB3A93C" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_ProceedsFromSaleOfRestrictedCommonStock" xlink:label="loc_flks_ProceedsFromSaleOfRestrictedCommonStock_69C29E741AB459E494740DF58F94C807" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_flks_ProceedsFromSaleOfRestrictedCommonStock_69C29E741AB459E494740DF58F94C807" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_BE8006E55A8B5EFD890015E5E08BBE7E" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_BE8006E55A8B5EFD890015E5E08BBE7E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_543E889B5D8D56DBB87E6314F95795C5" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_543E889B5D8D56DBB87E6314F95795C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockRepurchaseProgramPeriodInForce1" xlink:label="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_AD792E07B9AB5EE7BA61BC7185F0403D" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_StockRepurchaseProgramPeriodInForce1_AD792E07B9AB5EE7BA61BC7185F0403D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_5543FD82B5985C089E5151915949F443" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_5543FD82B5985C089E5151915949F443" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_2836C7C0FAA859A4A0CF5DA1F85B8879" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_D01AEFF9056752749B097F0E3C821022" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber_2836C7C0FAA859A4A0CF5DA1F85B8879" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CommonStockRestrictedCommonStockActivityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract_D77A12355432C6EB05FF91DC479E49A7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E1B1500C3DF1A97689FA91DC479EFFC8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityAbstract_D77A12355432C6EB05FF91DC479E49A7" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E1B1500C3DF1A97689FA91DC479EFFC8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_F20477E6E85BA7450F2791DC479E37B1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E1B1500C3DF1A97689FA91DC479EFFC8" xlink:to="loc_us-gaap_AwardTypeAxis_F20477E6E85BA7450F2791DC479E37B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_A995865C2B083D859ED891DC479E393D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_F20477E6E85BA7450F2791DC479E37B1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_A995865C2B083D859ED891DC479E393D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_0C8F2A0341DFE411938B91DC479FED5E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_A995865C2B083D859ED891DC479E393D" xlink:to="loc_us-gaap_RestrictedStockMember_0C8F2A0341DFE411938B91DC479FED5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_BA7DB216AAD870625F7391DC479F53BE" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E1B1500C3DF1A97689FA91DC479EFFC8" xlink:to="loc_us-gaap_TitleOfIndividualAxis_BA7DB216AAD870625F7391DC479F53BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_0FCE5DE7283C53F2D4A791DC479F9C05" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualAxis_BA7DB216AAD870625F7391DC479F53BE" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_0FCE5DE7283C53F2D4A791DC479F9C05" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_NonemployeeConsultantsandAdvisersMember" xlink:label="loc_flks_NonemployeeConsultantsandAdvisersMember_FFE5AE6C3F5126BC9D8F91DC479FF988" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_0FCE5DE7283C53F2D4A791DC479F9C05" xlink:to="loc_flks_NonemployeeConsultantsandAdvisersMember_FFE5AE6C3F5126BC9D8F91DC479FF988" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B2F6317C6ACBFBA2C83091DC479F7110" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_E1B1500C3DF1A97689FA91DC479EFFC8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B2F6317C6ACBFBA2C83091DC479F7110" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B2F6317C6ACBFBA2C83091DC479F7110" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_3302FCAD536229FC099191DC479FEB40" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_3302FCAD536229FC099191DC479FEB40" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_C94C072CAC4295CF64E691DC479FFC63" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_C94C072CAC4295CF64E691DC479FFC63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_496F61D8FFD2F0A40D1291DC479F55A4" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_496F61D8FFD2F0A40D1291DC479F55A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_AF66533E62D106AF25C691E6493F0341" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_AF66533E62D106AF25C691E6493F0341" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_15455584F327DCA8040691DC479F8CF0" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_10E8B31A8716B6EDC7B991DC479FA882" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_15455584F327DCA8040691DC479F8CF0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_B2F6317C6ACBFBA2C83091DC479F7110" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_AF6C40C773120298590A91DC47A05833" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_AF6C40C773120298590A91DC47A05833" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_05902430B5C068FB8ECC91DC47A01F83" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_05902430B5C068FB8ECC91DC47A01F83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_D64452115D79ED23F53291DC47A0A4AF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_D64452115D79ED23F53291DC47A0A4AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_EA95700C3CB6ABE1F8DD91E76797CC4B" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_EA95700C3CB6ABE1F8DD91E76797CC4B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_173F05A09C9C82A9269D91DC47A0CDA7" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_583A56CEA387C552A63B91DC479FB1E2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_173F05A09C9C82A9269D91DC47A0CDA7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CommonStockTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityAbstract" xlink:label="loc_us-gaap_EquityAbstract_9DAB77919F9359E9B1F70A4DA9CACBD2" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_1C0F17B536B557D58976A0433A47022A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityAbstract_9DAB77919F9359E9B1F70A4DA9CACBD2" xlink:to="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_1C0F17B536B557D58976A0433A47022A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CondensedConsolidatedBalanceSheetsUnaudited" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract_5C0BD7DFAF58685A4297CA6ACC3B8F0F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_5C0BD7DFAF58685A4297CA6ACC3B8F0F" xlink:to="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:to="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Cash" xlink:label="loc_us-gaap_Cash_AF0C739C84F7D24B37BECA6ACC3B2240" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_Cash_AF0C739C84F7D24B37BECA6ACC3B2240" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_21EEFCF80D62FD7B59ACCA6ACC3B2A45" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_21EEFCF80D62FD7B59ACCA6ACC3B2A45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_542DA15060335927BFFFCA6ACC402464" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_542DA15060335927BFFFCA6ACC402464" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_88223B2465F18A2B1D6ACA6ACC41CC5F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_InventoryNet_88223B2465F18A2B1D6ACA6ACC41CC5F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_1E5A1D850C128E420FB6CA6ACC41D595" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_1E5A1D850C128E420FB6CA6ACC41D595" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_33F32C1186A548A98390CA6ACC4190C5" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsCurrentAbstract_9DAAAF0ABA9567692D25CA6ACC3BB6DD" xlink:to="loc_us-gaap_AssetsCurrent_33F32C1186A548A98390CA6ACC4190C5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_8D122E0F826B8B713BF6CA6ACC414F83" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_8D122E0F826B8B713BF6CA6ACC414F83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_AF6DE80217C070C9C7CFCA6ACC414C9A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_AF6DE80217C070C9C7CFCA6ACC414C9A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalentsNoncurrent" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsNoncurrent_17433416F20E41BAA33ACA6ACC414D95" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsNoncurrent_17433416F20E41BAA33ACA6ACC414D95" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_BA4981CE6854A5F1DA19CA6ACC414BD4" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AssetsAbstract_15D3EF8BFC3A789E6AE0CA6ACC3BA454" xlink:to="loc_us-gaap_Assets_BA4981CE6854A5F1DA19CA6ACC414BD4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_F65C9C14BB33133742DCCA6ACC4174AB" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_5C0BD7DFAF58685A4297CA6ACC3B8F0F" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_F65C9C14BB33133742DCCA6ACC4174AB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_F65C9C14BB33133742DCCA6ACC4174AB" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_6FECACF852AEDFFECAC0CA6ACC41C10E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:to="loc_us-gaap_AccountsPayableCurrent_6FECACF852AEDFFECAC0CA6ACC41C10E" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_AccruedExpensesAndOtherCurrentLiabilities" xlink:label="loc_flks_AccruedExpensesAndOtherCurrentLiabilities_59459F785F0A1BEE8E71CA6ACC41F4B4" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:to="loc_flks_AccruedExpensesAndOtherCurrentLiabilities_59459F785F0A1BEE8E71CA6ACC41F4B4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="loc_us-gaap_DeferredRevenueCurrent_333881918167E6E60607CA6ACC4148DB" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:to="loc_us-gaap_DeferredRevenueCurrent_333881918167E6E60607CA6ACC4148DB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredRentCreditCurrent" xlink:label="loc_us-gaap_DeferredRentCreditCurrent_FE9862CABA4811698AD9CA6ACC413B78" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:to="loc_us-gaap_DeferredRentCreditCurrent_FE9862CABA4811698AD9CA6ACC413B78" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_033BFAE9EF383990318DCA6ACC423BA7" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_ABA9E90D67F52486978BCA6ACC4130B6" xlink:to="loc_us-gaap_LiabilitiesCurrent_033BFAE9EF383990318DCA6ACC423BA7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredRentCreditNoncurrent" xlink:label="loc_us-gaap_DeferredRentCreditNoncurrent_643801D3992BEB350A24CA6ACC42B6FD" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_F65C9C14BB33133742DCCA6ACC4174AB" xlink:to="loc_us-gaap_DeferredRentCreditNoncurrent_643801D3992BEB350A24CA6ACC42B6FD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_F822C7191E80B36F7806CA6ACC42DEC8" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_F65C9C14BB33133742DCCA6ACC4174AB" xlink:to="loc_us-gaap_Liabilities_F822C7191E80B36F7806CA6ACC42DEC8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_5C0BD7DFAF58685A4297CA6ACC3B8F0F" xlink:to="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_487F6348903D58BE1CABCA6ACC42E1D2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_PreferredStockValue_487F6348903D58BE1CABCA6ACC42E1D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_C5BC3C4585A65F829A9DCA6ACC425A24" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_CommonStockValue_C5BC3C4585A65F829A9DCA6ACC425A24" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="loc_us-gaap_AdditionalPaidInCapital_D6E2966A931FC5C058C7CA6ACC424863" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_AdditionalPaidInCapital_D6E2966A931FC5C058C7CA6ACC424863" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_0E1AE349D27D037E5D8BCA6ACC42DD26" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_0E1AE349D27D037E5D8BCA6ACC42DD26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_329254C92450B57A72FDCA6ACC427C8A" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_329254C92450B57A72FDCA6ACC427C8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_1BD19994A5348E15E1A5CA6ACC42B3F5" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StockholdersEquityAbstract_BCF02C029EFCF4850EB0CA6ACC425D64" xlink:to="loc_us-gaap_StockholdersEquity_1BD19994A5348E15E1A5CA6ACC42B3F5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_3F780E1583F0E8F0531DCA6ACC423E92" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_5C0BD7DFAF58685A4297CA6ACC3B8F0F" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_3F780E1583F0E8F0531DCA6ACC423E92" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CondensedConsolidatedBalanceSheetsUnauditedParenthetical" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_107D97AB70F35483953670ED928F483A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_107D97AB70F35483953670ED928F483A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_66891EE6E66555B98F3549DD8D7F4ABA" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_66891EE6E66555B98F3549DD8D7F4ABA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued_E34BD2FA7E735270ACEED083F8ACB94D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_PreferredStockSharesIssued_E34BD2FA7E735270ACEED083F8ACB94D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_ED85486A1DB35D838A22C233B84D5A14" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_ED85486A1DB35D838A22C233B84D5A14" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_186528B2014259D1B2ACDC6009569358" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_186528B2014259D1B2ACDC6009569358" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_44984597517F5C9CA31891155686801A" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_44984597517F5C9CA31891155686801A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_E12997836EFC5EA7A016E75E477C5547" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_CommonStockSharesIssued_E12997836EFC5EA7A016E75E477C5547" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_9243E27F10ED5696943F4EE2DA5C45B7" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_BC1FDAD1958D56D3A94BF4A60D5BB6CD" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_9243E27F10ED5696943F4EE2DA5C45B7" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfCashFlowsUnaudited" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:label="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_112FD1BF68CC0580D0DFCA51BB9A8C3F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_112FD1BF68CC0580D0DFCA51BB9A8C3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_A8100E4D7E51F8BCD835CA51BB9A5FAA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_112FD1BF68CC0580D0DFCA51BB9A8C3F" xlink:to="loc_us-gaap_NetIncomeLoss_A8100E4D7E51F8BCD835CA51BB9A5FAA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_112FD1BF68CC0580D0DFCA51BB9A8C3F" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_A73EF691274185E6D419CA51BB9A24ED" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:to="loc_us-gaap_Depreciation_A73EF691274185E6D419CA51BB9A24ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_860E326D5DF6FF6089C4CA51BB9ABEF9" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:to="loc_us-gaap_ShareBasedCompensation_860E326D5DF6FF6089C4CA51BB9ABEF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InvestmentIncomeAmortizationOfPremium" xlink:label="loc_us-gaap_InvestmentIncomeAmortizationOfPremium_3ACCEAA81ED16D01158FCA51BB9AB2B9" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:to="loc_us-gaap_InvestmentIncomeAmortizationOfPremium_3ACCEAA81ED16D01158FCA51BB9AB2B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:label="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_671E2A1EF215164AA133CA51BB9A89D7" xlink:to="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_5CEBDF4B4F23433338C5CA51BB9AA6D8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_5CEBDF4B4F23433338C5CA51BB9AA6D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_63C2C14697AA3439BB36CA51BB9A3199" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_63C2C14697AA3439BB36CA51BB9A3199" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_9B679A1FF91B9F7E7BB0CA51BB9A537B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_9B679A1FF91B9F7E7BB0CA51BB9A537B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInOtherNoncurrentAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_BD248FCDBCFEB004DC8CCA51BB9AE16F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherNoncurrentAssets_BD248FCDBCFEB004DC8CCA51BB9AE16F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_7D466972F0E68D1DE883CA51BB9A1FA2" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_7D466972F0E68D1DE883CA51BB9A1FA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_91D9735ACEC98E03D4C6CA51BB9BC91F" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilities_91D9735ACEC98E03D4C6CA51BB9BC91F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredRevenue" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_F02B67C9402510C68625CA51BB9B67EB" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredRevenue_F02B67C9402510C68625CA51BB9B67EB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInDeferredLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInDeferredLiabilities_383A6AB9CC78499CCBC5CA51BB9B7322" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_E256E985A4E7E39E3D1CCA51BB9A4071" xlink:to="loc_us-gaap_IncreaseDecreaseInDeferredLiabilities_383A6AB9CC78499CCBC5CA51BB9B7322" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_60CD805D2041509ACEA1CA51BB9BCAA6" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_112FD1BF68CC0580D0DFCA51BB9A8C3F" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_60CD805D2041509ACEA1CA51BB9BCAA6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:label="loc_us-gaap_PaymentsToAcquireMarketableSecurities_32902C4A6F25A77FF478CA51BB9B8BFD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:to="loc_us-gaap_PaymentsToAcquireMarketableSecurities_32902C4A6F25A77FF478CA51BB9B8BFD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:label="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_506D7786C752A96712D8CA51BB9B7820" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:to="loc_us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_506D7786C752A96712D8CA51BB9B7820" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_A4F9FD304F0DB59A968FCA51BB9B7C6E" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_A4F9FD304F0DB59A968FCA51BB9B7C6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_AC59BF70989243444EECCA51BB9BC40F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_AC59BF70989243444EECCA51BB9BC40F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_F11DB899104C69B8B9A7CA51BB9BC71C" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_9274E2A85DF641BC3359CA51BB9B7531" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_F11DB899104C69B8B9A7CA51BB9BC71C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_1D4536CD2C1D83EC1186CA51BB9B487B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_1D4536CD2C1D83EC1186CA51BB9B487B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_E8B0080CBD283C53770CCA51BB9B1124" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_1D4536CD2C1D83EC1186CA51BB9B487B" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_E8B0080CBD283C53770CCA51BB9B1124" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_25C44FA0B31C6CDFF834CA51BB9B5268" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_1D4536CD2C1D83EC1186CA51BB9B487B" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_25C44FA0B31C6CDFF834CA51BB9B5268" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashPeriodIncreaseDecrease_932869DD42A6EDD5D682CA51BB9B40D3" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_CashPeriodIncreaseDecrease_932869DD42A6EDD5D682CA51BB9B40D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Cash" xlink:label="loc_us-gaap_Cash_C67E2591953AECF43638CA51BB9BEDE1" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_Cash_C67E2591953AECF43638CA51BB9BEDE1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Cash" xlink:label="loc_us-gaap_Cash_DFBC5FDAB92C2EA97300CA51BB9B89A2" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_Cash_DFBC5FDAB92C2EA97300CA51BB9B89A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_3E14B0880C345F842DAFCA51BB9C85C8" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfCashFlowsAbstract_B1C915B32AB4A5463560CA51BB94B428" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_3E14B0880C345F842DAFCA51BB9C85C8" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_PropertyAndEquipmentPurchasesInAccruedExpense" xlink:label="loc_flks_PropertyAndEquipmentPurchasesInAccruedExpense_0F6FCB0FB1AC1E8191B1CA51BB9C9404" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_3E14B0880C345F842DAFCA51BB9C85C8" xlink:to="loc_flks_PropertyAndEquipmentPurchasesInAccruedExpense_0F6FCB0FB1AC1E8191B1CA51BB9C9404" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CapitalExpendituresIncurredButNotYetPaid" xlink:label="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_FF317219DA6F5CE71BC3CA51BB9CB4C6" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_3E14B0880C345F842DAFCA51BB9C85C8" xlink:to="loc_us-gaap_CapitalExpendituresIncurredButNotYetPaid_FF317219DA6F5CE71BC3CA51BB9CB4C6" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfComprehensiveLossUnaudited" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract" xlink:label="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_074BB069813A5388B5AEB0938705CA11" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_9C2DFC7A0E805A5ABA7D08B3C40DAC66" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_074BB069813A5388B5AEB0938705CA11" xlink:to="loc_us-gaap_NetIncomeLoss_9C2DFC7A0E805A5ABA7D08B3C40DAC66" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_0A51DD6A830E525E811B1748346A21D9" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_074BB069813A5388B5AEB0938705CA11" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_0A51DD6A830E525E811B1748346A21D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_C8636A81E5515C06A33D76C21BBDA8CF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_0A51DD6A830E525E811B1748346A21D9" xlink:to="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_C8636A81E5515C06A33D76C21BBDA8CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_10884989008755078D90E37F171EBAE1" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract_074BB069813A5388B5AEB0938705CA11" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_10884989008755078D90E37F171EBAE1" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/CondensedConsolidatedStatementsOfOperationsUnaudited" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:label="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="loc_us-gaap_SalesRevenueGoodsNet_5233A43D13DC52028E5D233B3DCC116A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_SalesRevenueGoodsNet_5233A43D13DC52028E5D233B3DCC116A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherSalesRevenueNet" xlink:label="loc_us-gaap_OtherSalesRevenueNet_6DBB88D47B505317993F790367171145" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_OtherSalesRevenueNet_6DBB88D47B505317993F790367171145" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_D6EBE919CF8D511798318DC3B0C85F81" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_SalesRevenueNet_D6EBE919CF8D511798318DC3B0C85F81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:label="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="loc_us-gaap_CostOfGoodsSold_B6797154EB9E5D2F927A7C2BCDA07412" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:to="loc_us-gaap_CostOfGoodsSold_B6797154EB9E5D2F927A7C2BCDA07412" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_EAD3378245AA5C7BB57CFEE9BB7A8B31" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_EAD3378245AA5C7BB57CFEE9BB7A8B31" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_082222E7C4AA51F982BC02474C3D744B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_082222E7C4AA51F982BC02474C3D744B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingExpenses" xlink:label="loc_us-gaap_OperatingExpenses_65DA9014ADC3568BAFE64B55D5A52379" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OperatingExpensesAbstract_62235706C0935052A19083002D45BE11" xlink:to="loc_us-gaap_OperatingExpenses_65DA9014ADC3568BAFE64B55D5A52379" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_2C8AD838BD515B739FD482401E7A8A5E" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_OperatingIncomeLoss_2C8AD838BD515B739FD482401E7A8A5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestIncomeOperating" xlink:label="loc_us-gaap_InterestIncomeOperating_E6E3F75575B752B0B73DA8F3526E4B07" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_InterestIncomeOperating_E6E3F75575B752B0B73DA8F3526E4B07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_0BD1B114A1F750BAB7D8C435AEA2440A" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_NetIncomeLoss_0BD1B114A1F750BAB7D8C435AEA2440A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_347125E56D245EF2AD3EEB60597D5650" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_347125E56D245EF2AD3EEB60597D5650" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="loc_us-gaap_EarningsPerShareBasicAndDiluted_1B1EC8F85B4B5AF6A1ECE501733A76BE" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_EarningsPerShareBasicAndDiluted_1B1EC8F85B4B5AF6A1ECE501733A76BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_713791E35FF25B7494C0C0D25E2C7CD5" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementAbstract_F5851D5372D75BECB2CDE0531C743D73" xlink:to="loc_us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted_713791E35FF25B7494C0C0D25E2C7CD5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/DocumentAndEntityInformation" xlink:type="extended">
    <link:loc xlink:href="flks-20170331.xsd#flks_DocumentAndEntityInformationAbstract" xlink:label="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_25635DDA008551819B58AD5F4AE64CBA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_EntityRegistrantName_25635DDA008551819B58AD5F4AE64CBA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_37CC5FB6138259F19DE63B5D33503D2F" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_EntityCentralIndexKey_37CC5FB6138259F19DE63B5D33503D2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_052CCD087A845899924285AA30194A9B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_CurrentFiscalYearEndDate_052CCD087A845899924285AA30194A9B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_EDDA6A96976354BDB45A8D5E4D398369" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_EntityFilerCategory_EDDA6A96976354BDB45A8D5E4D398369" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_7265AB66FBA95F04B63CBB480810267B" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_DocumentType_7265AB66FBA95F04B63CBB480810267B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_4C1A96466B3C5960BB61C75AAC9A229A" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_DocumentPeriodEndDate_4C1A96466B3C5960BB61C75AAC9A229A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_802CA56C997E5D93B4495BDC08A500C4" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_DocumentFiscalYearFocus_802CA56C997E5D93B4495BDC08A500C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_B5B6ABE4947B57D7AF0D9B0D2B8CDC03" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_DocumentFiscalPeriodFocus_B5B6ABE4947B57D7AF0D9B0D2B8CDC03" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_CA58C29493925F578B09CFF29B7C932A" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_AmendmentFlag_CA58C29493925F578B09CFF29B7C932A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_45158807239A5063AB24B184747A7996" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_flks_DocumentAndEntityInformationAbstract_64B3F56EC6AE5F4E9B157651B5EE4ECD" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_45158807239A5063AB24B184747A7996" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/FairValueMeasurements" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="loc_us-gaap_FairValueDisclosuresAbstract_E8CAA729515D5515AAD35366EF3C640F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:label="loc_us-gaap_FairValueDisclosuresTextBlock_D170C1D038595A4AB68432B153A61319" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosuresAbstract_E8CAA729515D5515AAD35366EF3C640F" xlink:to="loc_us-gaap_FairValueDisclosuresTextBlock_D170C1D038595A4AB68432B153A61319" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="loc_us-gaap_FairValueDisclosuresAbstract_01AF2905883918D0368FCA51BB41BFC4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosuresAbstract_01AF2905883918D0368FCA51BB41BFC4" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_82807CED9DC5F82BFE0CCA51BB4192E2" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_82807CED9DC5F82BFE0CCA51BB4192E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_55E29FF943DA0C3415F0CA51BB41154D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_82807CED9DC5F82BFE0CCA51BB4192E2" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_55E29FF943DA0C3415F0CA51BB41154D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_EE90E1D5DE61896C3C8DCA51BB4151CB" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_55E29FF943DA0C3415F0CA51BB41154D" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_EE90E1D5DE61896C3C8DCA51BB4151CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_65B6A16DA2D0D1FF509BCA51BB41BDCC" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_65B6A16DA2D0D1FF509BCA51BB41BDCC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_720BDC9E85CE2CC2AB06CA51BB4243C8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_65B6A16DA2D0D1FF509BCA51BB41BDCC" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_720BDC9E85CE2CC2AB06CA51BB4243C8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_73CBD86C99FF926A7B8ACA51BB42B3A1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_720BDC9E85CE2CC2AB06CA51BB4243C8" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_73CBD86C99FF926A7B8ACA51BB42B3A1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_CF00FE8B2894B79BF232CA51BB429A1B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_720BDC9E85CE2CC2AB06CA51BB4243C8" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_CF00FE8B2894B79BF232CA51BB429A1B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_33064DB7238B19208261CA51BB420469" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_720BDC9E85CE2CC2AB06CA51BB4243C8" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_33064DB7238B19208261CA51BB420469" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_3D9EC792F77960153FBCCA51BB42B24D" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_3D9EC792F77960153FBCCA51BB42B24D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:label="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_48C3428215E3BE304223CA51BB429B54" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis_3D9EC792F77960153FBCCA51BB42B24D" xlink:to="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_48C3428215E3BE304223CA51BB429B54" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateDebtSecuritiesMember" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_212052DCD672D4223B3BCA51BB42B6B0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_48C3428215E3BE304223CA51BB429B54" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_212052DCD672D4223B3BCA51BB42B6B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommercialPaperMember" xlink:label="loc_us-gaap_CommercialPaperMember_36E25A2339DBC0871C37CA51BB42DF7B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_48C3428215E3BE304223CA51BB429B54" xlink:to="loc_us-gaap_CommercialPaperMember_36E25A2339DBC0871C37CA51BB42DF7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_USGovernmentAgenciesDebtSecuritiesMember" xlink:label="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_DC67435CD35ABEF5BCEDCA51BB42EF36" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain_48C3428215E3BE304223CA51BB429B54" xlink:to="loc_us-gaap_USGovernmentAgenciesDebtSecuritiesMember_DC67435CD35ABEF5BCEDCA51BB42EF36" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3BB8D3CCF91AC72E8F71CA51BB42AB93" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3D843F7B732B3F6C6B23CA51BB41A7D5" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3BB8D3CCF91AC72E8F71CA51BB42AB93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_6F1B2286A584E685BA48CA51BB4259E3" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3BB8D3CCF91AC72E8F71CA51BB42AB93" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_6F1B2286A584E685BA48CA51BB4259E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesAbstract" xlink:label="loc_us-gaap_MarketableSecuritiesAbstract_C15E7E3DA89F2FDF89E5CA51BB42949A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3BB8D3CCF91AC72E8F71CA51BB42AB93" xlink:to="loc_us-gaap_MarketableSecuritiesAbstract_C15E7E3DA89F2FDF89E5CA51BB42949A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AvailableForSaleSecurities" xlink:label="loc_us-gaap_AvailableForSaleSecurities_E20FA63C5D3B141D3DE1CA51BB4785D8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_MarketableSecuritiesAbstract_C15E7E3DA89F2FDF89E5CA51BB42949A" xlink:to="loc_us-gaap_AvailableForSaleSecurities_E20FA63C5D3B141D3DE1CA51BB4785D8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsFairValueDisclosure" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_20837E5468C246B01112CA51BB481A48" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_3BB8D3CCF91AC72E8F71CA51BB42AB93" xlink:to="loc_us-gaap_AssetsFairValueDisclosure_20837E5468C246B01112CA51BB481A48" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/FairValueMeasurementsTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:label="loc_us-gaap_FairValueDisclosuresAbstract_106BB2D43DC552BC8088ED083E0E3B3E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock_C7EECBB3BD2C5C7A8B098A105CBDD251" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_FairValueDisclosuresAbstract_106BB2D43DC552BC8088ED083E0E3B3E" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock_C7EECBB3BD2C5C7A8B098A105CBDD251" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/IncomeTaxes" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_204B31F3E7775166B59D67B949EFF93A" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxDisclosureTextBlock" xlink:label="loc_us-gaap_IncomeTaxDisclosureTextBlock_2A2D3D1CFCB754F184BAF96B8808C1DE" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_204B31F3E7775166B59D67B949EFF93A" xlink:to="loc_us-gaap_IncomeTaxDisclosureTextBlock_2A2D3D1CFCB754F184BAF96B8808C1DE" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/IncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxDisclosureAbstract" xlink:label="loc_us-gaap_IncomeTaxDisclosureAbstract_C649FB2741CCF351EBF4AB98B70567EB" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_4992C2CB37B4BA83A6D5AB98B708C434" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeTaxDisclosureAbstract_C649FB2741CCF351EBF4AB98B70567EB" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_4992C2CB37B4BA83A6D5AB98B708C434" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/Inventory" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_C707ECAA8ED8536084013CD923396F1D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="loc_us-gaap_InventoryDisclosureTextBlock_B6F2E2A906615E5980D867D6B98E08EC" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_C707ECAA8ED8536084013CD923396F1D" xlink:to="loc_us-gaap_InventoryDisclosureTextBlock_B6F2E2A906615E5980D867D6B98E08EC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/InventoryDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_C5E76E6AB99262830C2A91DC47BB109C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_9F0188FEB2AFE46989F391DC47BB69B5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_C5E76E6AB99262830C2A91DC47BB109C" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_9F0188FEB2AFE46989F391DC47BB69B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryWorkInProcessNetOfReserves" xlink:label="loc_us-gaap_InventoryWorkInProcessNetOfReserves_7C5B436DFCC1FBDCA86391DC47BBABDF" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_C5E76E6AB99262830C2A91DC47BB109C" xlink:to="loc_us-gaap_InventoryWorkInProcessNetOfReserves_7C5B436DFCC1FBDCA86391DC47BBABDF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_F87EE8E5DAB53C0BBC9D91DC47BC7C3A" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_C5E76E6AB99262830C2A91DC47BB109C" xlink:to="loc_us-gaap_InventoryNet_F87EE8E5DAB53C0BBC9D91DC47BC7C3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryWriteDown" xlink:label="loc_us-gaap_InventoryWriteDown_BD4CF51DEB5831E7AD9191DC47BC76C4" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_C5E76E6AB99262830C2A91DC47BB109C" xlink:to="loc_us-gaap_InventoryWriteDown_BD4CF51DEB5831E7AD9191DC47BC76C4" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/InventoryTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="loc_us-gaap_InventoryDisclosureAbstract_774FB5EB024659709171B93CAD0C1077" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfInventoryCurrentTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_753CE81334C3500CAB063E15600AD997" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_InventoryDisclosureAbstract_774FB5EB024659709171B93CAD0C1077" xlink:to="loc_us-gaap_ScheduleOfInventoryCurrentTableTextBlock_753CE81334C3500CAB063E15600AD997" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/NetLossPerShare" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_DBBF5B46C9C45A85AA00773B7D523E77" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareTextBlock" xlink:label="loc_us-gaap_EarningsPerShareTextBlock_2DD59178762254489605B2906DDCF7A8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_DBBF5B46C9C45A85AA00773B7D523E77" xlink:to="loc_us-gaap_EarningsPerShareTextBlock_2DD59178762254489605B2906DDCF7A8" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/NetLossPerShareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_E5E451520411F202E30391DC474BDCFF" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_2C388EDD4B2A8731217B91DC474BD87F" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_E5E451520411F202E30391DC474BDCFF" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_2C388EDD4B2A8731217B91DC474BD87F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_AAE01F78CE45070BAEA991DC474BFB97" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_2C388EDD4B2A8731217B91DC474BD87F" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_AAE01F78CE45070BAEA991DC474BFB97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BB76369062A9099EA21891DC474BBE21" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_AAE01F78CE45070BAEA991DC474BFB97" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BB76369062A9099EA21891DC474BBE21" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1F58908528D8870ADDF891DC474BE557" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BB76369062A9099EA21891DC474BBE21" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1F58908528D8870ADDF891DC474BE557" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_2D4A98690AB5B5363D2E91DC474B4BD3" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_BB76369062A9099EA21891DC474BBE21" xlink:to="loc_us-gaap_RestrictedStockMember_2D4A98690AB5B5363D2E91DC474B4BD3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4FEC9A78BA06493C834691DC474C5A76" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_2C388EDD4B2A8731217B91DC474BD87F" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4FEC9A78BA06493C834691DC474C5A76" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_D7C1EEF36A99B620BBE991DC474C5BF0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4FEC9A78BA06493C834691DC474C5A76" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_D7C1EEF36A99B620BBE991DC474C5BF0" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/NetLossPerShareTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareAbstract" xlink:label="loc_us-gaap_EarningsPerShareAbstract_5A7E3BC711395D20986E035BFC264346" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_D5C0C67BB8D956FAB7EC84148079E6AD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EarningsPerShareAbstract_5A7E3BC711395D20986E035BFC264346" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_D5C0C67BB8D956FAB7EC84148079E6AD" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/OrganizationAndOperations" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_B2ED56B7F6DC561AA3CFA20B0CF795BE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_7B3D288798EF535F813B2E8E2A33F1C5" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_B2ED56B7F6DC561AA3CFA20B0CF795BE" xlink:to="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureTextBlock_7B3D288798EF535F813B2E8E2A33F1C5" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/OrganizationAndOperationsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract" xlink:label="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_DC4593A0D6ECA2E54E1C91DC482F9C32" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="loc_us-gaap_NumberOfReportableSegments_A3BF9C21110173C3A0B991DC483022BD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_DC4593A0D6ECA2E54E1C91DC482F9C32" xlink:to="loc_us-gaap_NumberOfReportableSegments_A3BF9C21110173C3A0B991DC483022BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_FC68BC36B7FF541FC71C91DC48307A78" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_DC4593A0D6ECA2E54E1C91DC482F9C32" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_FC68BC36B7FF541FC71C91DC48307A78" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashCashEquivalentsAndShortTermInvestments" xlink:label="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_E26B21A49B7763DA196591DC4830D124" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_DC4593A0D6ECA2E54E1C91DC482F9C32" xlink:to="loc_us-gaap_CashCashEquivalentsAndShortTermInvestments_E26B21A49B7763DA196591DC4830D124" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SegmentInformation" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_237F0FD6A5F7529A9ED07DA3B2C31582" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingDisclosureTextBlock" xlink:label="loc_us-gaap_SegmentReportingDisclosureTextBlock_FFDA4CBF02E95DCDB6487B4B969B4F0E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_237F0FD6A5F7529A9ED07DA3B2C31582" xlink:to="loc_us-gaap_SegmentReportingDisclosureTextBlock_FFDA4CBF02E95DCDB6487B4B969B4F0E" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_8DB6C0A217B65EF39B93288B1AE07540" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="loc_us-gaap_NumberOfReportableSegments_958C7600891F5A79B2C6E40F5D9FBD1A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_8DB6C0A217B65EF39B93288B1AE07540" xlink:to="loc_us-gaap_NumberOfReportableSegments_958C7600891F5A79B2C6E40F5D9FBD1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A0B0D73B4FCB5E228B11FE1C430AF45C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_8DB6C0A217B65EF39B93288B1AE07540" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A0B0D73B4FCB5E228B11FE1C430AF45C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsAxis" xlink:label="loc_us-gaap_ConsolidationItemsAxis_4078A4CC107C5DE5A5E08CDB04C3A4FF" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A0B0D73B4FCB5E228B11FE1C430AF45C" xlink:to="loc_us-gaap_ConsolidationItemsAxis_4078A4CC107C5DE5A5E08CDB04C3A4FF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationItemsDomain" xlink:label="loc_us-gaap_ConsolidationItemsDomain_608499F85B625F0384B57EB3C5529270" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConsolidationItemsAxis_4078A4CC107C5DE5A5E08CDB04C3A4FF" xlink:to="loc_us-gaap_ConsolidationItemsDomain_608499F85B625F0384B57EB3C5529270" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingSegmentsMember" xlink:label="loc_us-gaap_OperatingSegmentsMember_607A5EE7E2AC5333ADD82C15A912104A" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConsolidationItemsDomain_608499F85B625F0384B57EB3C5529270" xlink:to="loc_us-gaap_OperatingSegmentsMember_607A5EE7E2AC5333ADD82C15A912104A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_C8738ED4BE4954C9B380DF2C76D34354" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ConsolidationItemsDomain_608499F85B625F0384B57EB3C5529270" xlink:to="loc_us-gaap_CorporateNonSegmentMember_C8738ED4BE4954C9B380DF2C76D34354" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_BD2176BC122E5180AF232F74904AC877" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A0B0D73B4FCB5E228B11FE1C430AF45C" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_BD2176BC122E5180AF232F74904AC877" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_0768D1052C705CE39350D6B9D8AEBFD8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_BD2176BC122E5180AF232F74904AC877" xlink:to="loc_us-gaap_SegmentDomain_0768D1052C705CE39350D6B9D8AEBFD8" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_ConsumerOperationsMember" xlink:label="loc_flks_ConsumerOperationsMember_64A9215CA96A59F18F4098BD534EA944" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentDomain_0768D1052C705CE39350D6B9D8AEBFD8" xlink:to="loc_flks_ConsumerOperationsMember_64A9215CA96A59F18F4098BD534EA944" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_DrugDevelopmentMember" xlink:label="loc_flks_DrugDevelopmentMember_E9FA63E62AC65B5DB91B52E2D972DA6E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentDomain_0768D1052C705CE39350D6B9D8AEBFD8" xlink:to="loc_flks_DrugDevelopmentMember_E9FA63E62AC65B5DB91B52E2D972DA6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_22A51800DD6F56A3931C805A0F0227E2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_A0B0D73B4FCB5E228B11FE1C430AF45C" xlink:to="loc_us-gaap_SegmentReportingInformationLineItems_22A51800DD6F56A3931C805A0F0227E2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_375ED8EF281A56C9A53067002417F112" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_22A51800DD6F56A3931C805A0F0227E2" xlink:to="loc_us-gaap_SalesRevenueNet_375ED8EF281A56C9A53067002417F112" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestIncomeOperating" xlink:label="loc_us-gaap_InterestIncomeOperating_C22FDF7FA6BF5461B7742D848382D571" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_22A51800DD6F56A3931C805A0F0227E2" xlink:to="loc_us-gaap_InterestIncomeOperating_C22FDF7FA6BF5461B7742D848382D571" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_83CAA53217C05E859D07A1263B5493B9" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_22A51800DD6F56A3931C805A0F0227E2" xlink:to="loc_us-gaap_OperatingIncomeLoss_83CAA53217C05E859D07A1263B5493B9" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SegmentInformationTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:label="loc_us-gaap_SegmentReportingAbstract_7BD65242248E51A580F9E6D6CBD52B21" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock" xlink:label="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock_F6C7725EE26156359453E3E471B0A82B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_SegmentReportingAbstract_7BD65242248E51A580F9E6D6CBD52B21" xlink:to="loc_us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTextBlock_F6C7725EE26156359453E3E471B0A82B" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/StockBasedCompensation" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_7D612C1DB6EC534BAF018BA4C914A382" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_D4261306D99D50F88C91AB514BF8ED46" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_7D612C1DB6EC534BAF018BA4C914A382" xlink:to="loc_us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_D4261306D99D50F88C91AB514BF8ED46" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/StockBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_77B58B679EDC5F1713F191DC47917722" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_77B58B679EDC5F1713F191DC47917722" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_1001B8CEBB99ABC87B3D91DC479246A8" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:to="loc_us-gaap_PlanNameAxis_1001B8CEBB99ABC87B3D91DC479246A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_51C31AEA54A86798DFD291DC479257F9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameAxis_1001B8CEBB99ABC87B3D91DC479246A8" xlink:to="loc_us-gaap_PlanNameDomain_51C31AEA54A86798DFD291DC479257F9" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_FlexPharmaInc.2014EquityIncentivePlanMember" xlink:label="loc_flks_FlexPharmaInc.2014EquityIncentivePlanMember_2848C80835853C4F922D91DC479204DD" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameDomain_51C31AEA54A86798DFD291DC479257F9" xlink:to="loc_flks_FlexPharmaInc.2014EquityIncentivePlanMember_2848C80835853C4F922D91DC479204DD" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_EquityIncentivePlan2015Member" xlink:label="loc_flks_EquityIncentivePlan2015Member_2552B5FC5FDEAC3F875D91DC4792FF80" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_PlanNameDomain_51C31AEA54A86798DFD291DC479257F9" xlink:to="loc_flks_EquityIncentivePlan2015Member_2552B5FC5FDEAC3F875D91DC4792FF80" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_7AAF87A56F10ED05BCE291DC4792106C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:to="loc_us-gaap_RangeAxis_7AAF87A56F10ED05BCE291DC4792106C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_9C8F976AEA2357D4AE3A91DC47928D8B" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeAxis_7AAF87A56F10ED05BCE291DC4792106C" xlink:to="loc_us-gaap_RangeMember_9C8F976AEA2357D4AE3A91DC47928D8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_A57A7F6ECECE7BA6913D91DC4792C5B7" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_9C8F976AEA2357D4AE3A91DC47928D8B" xlink:to="loc_us-gaap_MinimumMember_A57A7F6ECECE7BA6913D91DC4792C5B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_00DFB1DF66DC5D7599D391DC4792EE6C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_RangeMember_9C8F976AEA2357D4AE3A91DC47928D8B" xlink:to="loc_us-gaap_MaximumMember_00DFB1DF66DC5D7599D391DC4792EE6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_FD060316251BF55AD5ED91DC4793DBA7" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:to="loc_us-gaap_AwardTypeAxis_FD060316251BF55AD5ED91DC4793DBA7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_356F3D0DC1BB306D58D091DC4793C2B1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AwardTypeAxis_FD060316251BF55AD5ED91DC4793DBA7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_356F3D0DC1BB306D58D091DC4793C2B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_7C93223E654145755F7791DC47933267" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_356F3D0DC1BB306D58D091DC4793C2B1" xlink:to="loc_us-gaap_EmployeeStockOptionMember_7C93223E654145755F7791DC47933267" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7C0B31F00AAAF153BB1091DC4792E8E4" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_4E0BF55C1430A31F300691DC47932C0E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_4E0BF55C1430A31F300691DC47932C0E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_12BCEB29C007D1A854FC91DC4793EE0C" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_12BCEB29C007D1A854FC91DC4793EE0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_869E599CA71FB8C8125891DC4793689F" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_869E599CA71FB8C8125891DC4793689F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_99DC7FD954F9C2DD995C91DC4793877C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_99DC7FD954F9C2DD995C91DC4793877C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_514EF5940821B67C3A4591DC4794E921" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_514EF5940821B67C3A4591DC4794E921" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6F7571AD59EEE09E336291DC4794D8DC" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_39CB8990488550932CFC91DC47930163" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6F7571AD59EEE09E336291DC4794D8DC" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/StockBasedCompensationSummaryOfStockBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_1B15D0E7BD8C5791AA616131466B4E25" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_685996899F71505DB7FA22E718BB3E26" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_1B15D0E7BD8C5791AA616131466B4E25" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_685996899F71505DB7FA22E718BB3E26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_8B42010B0D525BE4A0F5F8E4BA5C60EA" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_685996899F71505DB7FA22E718BB3E26" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_8B42010B0D525BE4A0F5F8E4BA5C60EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6950CDF56AC6561992628ACBA10902F9" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8B42010B0D525BE4A0F5F8E4BA5C60EA" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6950CDF56AC6561992628ACBA10902F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ResearchAndDevelopmentExpenseMember" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_20BF19D9CECD5DE6ABE88755A70E7213" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6950CDF56AC6561992628ACBA10902F9" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_20BF19D9CECD5DE6ABE88755A70E7213" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_1005790B633358C69B44307A95107418" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6950CDF56AC6561992628ACBA10902F9" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_1005790B633358C69B44307A95107418" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_36B3823418E259FDAA31114CCEDC1C3B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_685996899F71505DB7FA22E718BB3E26" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_36B3823418E259FDAA31114CCEDC1C3B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_D8D550D6D9F05481B0D702B830F2A232" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_36B3823418E259FDAA31114CCEDC1C3B" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_D8D550D6D9F05481B0D702B830F2A232" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/StockBasedCompensationSummaryOfStockOptionActivityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_0CA5D0B4A4ED7472FE5791DC4783FC55" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_0CA5D0B4A4ED7472FE5791DC4783FC55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_BF97EB4DC010601137A291DC47839381" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_BF97EB4DC010601137A291DC47839381" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_81AB6EEF1EA973DAF05991DC4783A2AE" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_81AB6EEF1EA973DAF05991DC4783A2AE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_AB48566A6D37EDA85F5B91DC4784177F" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_AB48566A6D37EDA85F5B91DC4784177F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_A9FF6449457E3D3B172891DC47845353" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_A90AF266C57910217C9791DC47836A45" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_A9FF6449457E3D3B172891DC47845353" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_1E5F2CF25EA925B8F9F291DC47843592" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_1E5F2CF25EA925B8F9F291DC47843592" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_6495C7F3A68A73F00AE791DC478493F9" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber_6495C7F3A68A73F00AE791DC478493F9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2C1054D3A34B5CAF3B1C91DC47848285" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_2C1054D3A34B5CAF3B1C91DC47848285" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_EC09301A9C3D2A8CC08991DC47843FD7" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_EC09301A9C3D2A8CC08991DC47843FD7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_CE648A026D7461705CD191DC4784DFCF" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_CE648A026D7461705CD191DC4784DFCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_15EC7AF44E27C8B3317A91DC478A319A" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_15EC7AF44E27C8B3317A91DC478A319A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_C3C17218E430344B676091DC478AA56A" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_0A671995E9A9491E1D8591DC4784E239" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_C3C17218E430344B676091DC478AA56A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_58D19066381BB732979291DC478A1DCA" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_58D19066381BB732979291DC478A1DCA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_4BC5DD9BB3291A4845C791DC478B10BE" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice_4BC5DD9BB3291A4845C791DC478B10BE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_8044EBA9CDD047028E1691DC47830A93" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_7177160F84C7D1CA89A391DC478BEF6E" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_7177160F84C7D1CA89A391DC478BEF6E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_9E400CC0B2846A45503491DC478BD75E" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_9E400CC0B2846A45503491DC478BD75E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_225566C94474FC7B194191DC478BAD4F" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1_225566C94474FC7B194191DC478BAD4F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_C72767414E265C31CA7F91DC478B9347" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_C72767414E265C31CA7F91DC478B9347" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_EAFE5E4EB9E94A24622691DC478B03C7" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_EAFE5E4EB9E94A24622691DC478B03C7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_3BADD0B07AE4D927C01E91DC478B1A84" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract_71F1748A230F9087FF4D91DC478B31BC" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue_3BADD0B07AE4D927C01E91DC478B1A84" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/StockBasedCompensationTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:label="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9358180193D0500FB7F1786D286E4603" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_7A0D378BCFD659C5A0F3F0ACB87C1E14" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9358180193D0500FB7F1786D286E4603" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_7A0D378BCFD659C5A0F3F0ACB87C1E14" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_551392665EB652648619729DD42C3C9A" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_9358180193D0500FB7F1786D286E4603" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_551392665EB652648619729DD42C3C9A" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncements" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_47F869F74D6256BEB5FF2650AA09A892" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SignificantAccountingPoliciesTextBlock" xlink:label="loc_us-gaap_SignificantAccountingPoliciesTextBlock_D02DAAAB47B6587A829EF7C322C6E535" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_47F869F74D6256BEB5FF2650AA09A892" xlink:to="loc_us-gaap_SignificantAccountingPoliciesTextBlock_D02DAAAB47B6587A829EF7C322C6E535" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_D0101D8630B52F072B99AB9A1A8E2A91" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_DFCAD14D64BD42B8E1C8AB9C748CD122" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_D0101D8630B52F072B99AB9A1A8E2A91" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_DFCAD14D64BD42B8E1C8AB9C748CD122" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_45D79FDB6AB2A1668790AB9DAA5A4052" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_DFCAD14D64BD42B8E1C8AB9C748CD122" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_45D79FDB6AB2A1668790AB9DAA5A4052" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_99828BD2DB3C081F2609AB9DAA5BC4D1" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_45D79FDB6AB2A1668790AB9DAA5A4052" xlink:to="loc_us-gaap_EquityComponentDomain_99828BD2DB3C081F2609AB9DAA5BC4D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_4F3B31837599F6487E1FAB9DCBC03B2C" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_EquityComponentDomain_99828BD2DB3C081F2609AB9DAA5BC4D1" xlink:to="loc_us-gaap_RetainedEarningsMember_4F3B31837599F6487E1FAB9DCBC03B2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_447888770ECE2BBC74C4AB9CBE4B5D3D" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_DFCAD14D64BD42B8E1C8AB9C748CD122" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_447888770ECE2BBC74C4AB9CBE4B5D3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_53C1999F7C047A33453EAB9CBE53D25D" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_447888770ECE2BBC74C4AB9CBE4B5D3D" xlink:to="loc_us-gaap_TypeOfAdoptionMember_53C1999F7C047A33453EAB9CBE53D25D" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_AccountingStandardsUpdate201609Member" xlink:label="loc_flks_AccountingStandardsUpdate201609Member_111D53175E8AEFBF06C1AB9CED0B98D0" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_TypeOfAdoptionMember_53C1999F7C047A33453EAB9CBE53D25D" xlink:to="loc_flks_AccountingStandardsUpdate201609Member_111D53175E8AEFBF06C1AB9CED0B98D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_DFCAD14D64BD42B8E1C8AB9C748CD122" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:type="arc" />
    <link:loc xlink:href="flks-20170331.xsd#flks_RevenueRecognitionRefundPeriod" xlink:label="loc_flks_RevenueRecognitionRefundPeriod_1D55E120D23C06F78840AB9A1A8E5D28" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:to="loc_flks_RevenueRecognitionRefundPeriod_1D55E120D23C06F78840AB9A1A8E5D28" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdvertisingExpense" xlink:label="loc_us-gaap_AdvertisingExpense_E8719094E56566F90B0EAB9A1A8E718B" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:to="loc_us-gaap_AdvertisingExpense_E8719094E56566F90B0EAB9A1A8E718B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShippingHandlingAndTransportationCosts" xlink:label="loc_us-gaap_ShippingHandlingAndTransportationCosts_A4E1CBD136E1F78EDA67AB9A1A8E832B" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:to="loc_us-gaap_ShippingHandlingAndTransportationCosts_A4E1CBD136E1F78EDA67AB9A1A8E832B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption" xlink:label="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_6BFDDA3D258A8244261BAB9B5757C5A4" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:to="loc_us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption_6BFDDA3D258A8244261BAB9B5757C5A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_D6254139D53BEA63B4E6ABA256424CC2" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_C88DE9EC77C831E62F45AB9C748D22E2" xlink:to="loc_us-gaap_DeferredTaxAssetsLiabilitiesNet_D6254139D53BEA63B4E6ABA256424CC2" xlink:type="arc" />
  </link:presentationLink>
  <link:presentationLink xlink:role="http://www.flex-pharma.com/role/SummaryOfSignificantAccountingPoliciesAndRecentAccountingPronouncementsPolicies" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:label="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:label="loc_us-gaap_RevenueRecognitionPolicyTextBlock_E0CFADA0593528DDB88191DC47E60AD6" xlink:type="locator" />
    <link:presentationArc order="1" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_RevenueRecognitionPolicyTextBlock_E0CFADA0593528DDB88191DC47E60AD6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevenueRecognitionRevenueReductions" xlink:label="loc_us-gaap_RevenueRecognitionRevenueReductions_916FDA62DD2BA3DFCF5D91DC47E6EC47" xlink:type="locator" />
    <link:presentationArc order="2" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_RevenueRecognitionRevenueReductions_916FDA62DD2BA3DFCF5D91DC47E6EC47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReceivablesPolicyTextBlock" xlink:label="loc_us-gaap_ReceivablesPolicyTextBlock_1463CB66BA3B8840A4AC91DC47E6ED79" xlink:type="locator" />
    <link:presentationArc order="3" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_ReceivablesPolicyTextBlock_1463CB66BA3B8840A4AC91DC47E6ED79" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicy" xlink:label="loc_us-gaap_ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicy_23E3FD998556FFE9E35E91DC47E6902C" xlink:type="locator" />
    <link:presentationArc order="4" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_ReceivablesTradeAndOtherAccountsReceivableAllowanceForDoubtfulAccountsPolicy_23E3FD998556FFE9E35E91DC47E6902C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdvertisingCostsPolicyTextBlock" xlink:label="loc_us-gaap_AdvertisingCostsPolicyTextBlock_26EE1B1182F11F0DA12791DC47E7C5F4" xlink:type="locator" />
    <link:presentationArc order="5" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_AdvertisingCostsPolicyTextBlock_26EE1B1182F11F0DA12791DC47E7C5F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShippingAndHandlingCostPolicyTextBlock" xlink:label="loc_us-gaap_ShippingAndHandlingCostPolicyTextBlock_ABECD1559B93305D005291DC47E7069A" xlink:type="locator" />
    <link:presentationArc order="6" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_ShippingAndHandlingCostPolicyTextBlock_ABECD1559B93305D005291DC47E7069A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BasisOfAccountingPolicyPolicyTextBlock" xlink:label="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_ECA8A37384F7B841CF4791DC47E74F43" xlink:type="locator" />
    <link:presentationArc order="7" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_BasisOfAccountingPolicyPolicyTextBlock_ECA8A37384F7B841CF4791DC47E74F43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="loc_us-gaap_UseOfEstimates_F79ED6A6B7B62577AE6C91DC47E73ADD" xlink:type="locator" />
    <link:presentationArc order="8" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_UseOfEstimates_F79ED6A6B7B62577AE6C91DC47E73ADD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:label="loc_us-gaap_ConsolidationPolicyTextBlock_8FD1CA85A3D264BAFB7F91DC47E709C2" xlink:type="locator" />
    <link:presentationArc order="9" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_ConsolidationPolicyTextBlock_8FD1CA85A3D264BAFB7F91DC47E709C2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:label="loc_us-gaap_ConcentrationRiskCreditRisk_B12AA65ABD5580B7FEC191DC47E75A3F" xlink:type="locator" />
    <link:presentationArc order="10" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_ConcentrationRiskCreditRisk_B12AA65ABD5580B7FEC191DC47E75A3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_7C8D85C6A09FE6DA420A91DC47E7482B" xlink:type="locator" />
    <link:presentationArc order="11" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_7C8D85C6A09FE6DA420A91DC47E7482B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementPolicyPolicyTextBlock" xlink:label="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_16983717C1AEA026CADC91DC47E78A8F" xlink:type="locator" />
    <link:presentationArc order="12" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_FairValueMeasurementPolicyPolicyTextBlock_16983717C1AEA026CADC91DC47E78A8F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsPolicyTextBlock" xlink:label="loc_us-gaap_CashAndCashEquivalentsPolicyTextBlock_718F371A10DE34CB525091DC47E7D833" xlink:type="locator" />
    <link:presentationArc order="13" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_CashAndCashEquivalentsPolicyTextBlock_718F371A10DE34CB525091DC47E7D833" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MarketableSecuritiesPolicy" xlink:label="loc_us-gaap_MarketableSecuritiesPolicy_B31E901557DC4A54DC0191DC47E79B8C" xlink:type="locator" />
    <link:presentationArc order="14" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_AccountingPoliciesAbstract_3345DD3443DDF753EB5491DC47E67DDD" xlink:to="loc_us-gaap_MarketableSecuritiesPolicy_B31E901557DC4A54DC0191DC47E79B8C" xlink:type="arc" />
  </link:presentationLink>
</link:linkbase>





