<SEC-DOCUMENT>0000899243-22-039583.txt : 20221230
<SEC-HEADER>0000899243-22-039583.hdr.sgml : 20221230
<ACCEPTANCE-DATETIME>20221230170036
ACCESSION NUMBER:		0000899243-22-039583
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20221228
FILED AS OF DATE:		20221230
DATE AS OF CHANGE:		20221230

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Korenberg Matthew E
		CENTRAL INDEX KEY:			0001649903

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33093
		FILM NUMBER:		221502489

	MAIL ADDRESS:	
		STREET 1:		11119 NORTH TORREY PINES ROAD
		STREET 2:		SUITE 200
		CITY:			LA JOLLA
		STATE:			CA
		ZIP:			92037

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIGAND PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0000886163
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				770160744
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		STREET 2:		SUITE 110
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		858-550-7500

	MAIL ADDRESS:	
		STREET 1:		3911 SORRENTO VALLEY BLVD
		STREET 2:		SUITE 110
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-12-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000886163</issuerCik>
        <issuerName>LIGAND PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>LGND</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001649903</rptOwnerCik>
            <rptOwnerName>Korenberg Matthew E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3911 SORRENTO VALLEY BOULEVARD,</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 110</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-12-28</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3859</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>66.29</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>92569</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Andrew Reardon, Attorney-in-Fact for Matthew E. Korenberg</signatureName>
        <signatureDate>2022-12-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
