<SEC-DOCUMENT>0001596771-18-000019.txt : 20180212
<SEC-HEADER>0001596771-18-000019.hdr.sgml : 20180212
<ACCEPTANCE-DATETIME>20180212163100
ACCESSION NUMBER:		0001596771-18-000019
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180208
FILED AS OF DATE:		20180212
DATE AS OF CHANGE:		20180212

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Gullans Steven R. Ph.D.
		CENTRAL INDEX KEY:			0001571997

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37809
		FILM NUMBER:		18596863

	MAIL ADDRESS:	
		STREET 1:		C/O EXCEL VENTURE MANAGEMENT, LLC
		STREET 2:		800 BOYLSTON ST., STE 2825
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02199

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Gemphire Therapeutics Inc.
		CENTRAL INDEX KEY:			0001638287
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				472389984
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		17199 N. LAUREL PARK DRIVE
		STREET 2:		SUITE 401
		CITY:			LIVONIA
		STATE:			MI
		ZIP:			48152
		BUSINESS PHONE:		248-980-6538

	MAIL ADDRESS:	
		STREET 1:		17199 N. LAUREL PARK DRIVE
		STREET 2:		SUITE 401
		CITY:			LIVONIA
		STATE:			MI
		ZIP:			48152
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-02-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001638287</issuerCik>
        <issuerName>Gemphire Therapeutics Inc.</issuerName>
        <issuerTradingSymbol>GEMP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001571997</rptOwnerCik>
            <rptOwnerName>Gullans Steven R. Ph.D.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>17199 N. LAUREL PARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 401</rptOwnerStreet2>
            <rptOwnerCity>LIVONIA</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48152</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Interim President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-02-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>71429</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>930252</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Excel Venture Fund II, L.P.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares were purchased in a confidentially marketed public offering pursuant to an Underwriting Agreement. The offering closed on February 12, 2018.</footnote>
        <footnote id="F2">The reporting person, as the Manager of Excel Venture Fund II, L.P., beneficially owns the reported securities indirectly, but disclaims beneficial ownership of the securities except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Stephanie Swan, by Power of Attorney</signatureName>
        <signatureDate>2018-02-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
