<?xml version="1.0" encoding="US-ASCII"?>
<!-- DFIN New ActiveDisclosure (SM) XBRL Linkbase Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date :2023-03-17T15:49:36.4182+00:00 -->
<!-- Copyright (c) 2023 Donnelly Financial Solutions, Inc. All Rights Reserved. -->
<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:labelLink xlink:role="http://www.xbrl.org/2003/role/link" xlink:title="labelLink" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:href="evok-20230317.xsd#evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
    <link:loc xlink:type="locator" xlink:href="evok-20230317.xsd#evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember"/>
    <link:loc xlink:type="locator" xlink:href="evok-20230317.xsd#evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityRegistrantName" xlink:label="dei_EntityRegistrantName"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_DocumentType" xlink:label="dei_DocumentType"/>
    <link:loc xlink:type="locator" xlink:href="evok-20230317.xsd#evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember" xlink:label="evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityCentralIndexKey" xlink:label="dei_EntityCentralIndexKey"/>
    <link:loc xlink:type="locator" xlink:href="evok-20230317.xsd#evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember"/>
    <link:loc xlink:type="locator" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_CoverAbstract" xlink:label="dei_CoverAbstract"/>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase/Deduction for Awards Granted During Prior FY that were Outstanding and Unvested as of Applicable FY End Determined Based on Change in ASC 718 Fair Value from Prior FY End to Applicable FY End [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase deduction for awards granted during prior FY that were outstanding and unvested as of applicable FY end determined based on change in ASC 718 fair value from prior FY end to applicable FY end.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_AmendmentFlag_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment Flag</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase Based on ASC 718 Fair Value of Awards Granted during Applicable FY that Remain Unvested [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase based on ASC 718 fair value of awards granted during applicable FY that remain unvested.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase/Deduction for Awards Granted During Prior FY that Vested During Applicable FY Determined Based on Change in ASC 718 Fair Value from Prior FY End to Vesting Date [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase deduction for awards granted during prior FY that vested during applicable FY determined based on change in ASC 718 fair value from prior FY end to vesting date.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Registrant Name</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Type</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deduction for Amounts Reported under the Stock Awards and Option Awards Columns in the Summary Compensation Table [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Deduction for amounts reported under the stock awards and option awards columns in the summary compensation table.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase Based on ASC 718 Fair Value of Awards Granted during Applicable FY that Vested [Member]</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase based on ASC 718 fair value of awards granted during applicable FY that vested.</link:label>
    <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember" xlink:to="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatWereOutstandingAndUnvestedAsOfApplicableFyEndDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToApplicableFyEndMember_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember" xlink:to="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatRemainUnvestedMember_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember" xlink:to="evok_IncreaseDeductionForAwardsGrantedDuringPriorFyThatVestedDuringApplicableFyDeterminedBasedOnChangeInAsc718FairValueFromPriorFyEndToVestingDateMember_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityRegistrantName" xlink:to="dei_EntityRegistrantName_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentType" xlink:to="dei_DocumentType_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember" xlink:to="evok_DeductionForAmountsReportedUnderTheStockAwardsAndOptionAwardsColumnsInTheSummaryCompensationTableMember_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCentralIndexKey" xlink:to="dei_EntityCentralIndexKey_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember" xlink:to="evok_IncreaseBasedOnAsc718FairValueOfAwardsGrantedDuringApplicableFyThatVestedMember_lbl"/>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CoverAbstract" xlink:to="dei_CoverAbstract_lbl"/>
  </link:labelLink>
</link:linkbase>
