<SEC-DOCUMENT>0001415889-25-024451.txt : 20250912
<SEC-HEADER>0001415889-25-024451.hdr.sgml : 20250912
<ACCEPTANCE-DATETIME>20250912182522
ACCESSION NUMBER:		0001415889-25-024451
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250910
FILED AS OF DATE:		20250912
DATE AS OF CHANGE:		20250912

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Luse Rebecca
		CENTRAL INDEX KEY:			0002031342
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-42831
		FILM NUMBER:		251312700

	MAIL ADDRESS:	
		STREET 1:		C/O LB PHARMACEUTICALS INC
		STREET 2:		575 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LB PHARMACEUTICALS INC
		CENTRAL INDEX KEY:			0001691082
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		575 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		917-450-6581

	MAIL ADDRESS:	
		STREET 1:		575 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LB PHARMACEUTICALS INC.
		DATE OF NAME CHANGE:	20161129
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4-09122025_060917.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-09-10</periodOfReport>

    <issuer>
        <issuerCik>0001691082</issuerCik>
        <issuerName>LB PHARMACEUTICALS INC</issuerName>
        <issuerTradingSymbol>LBRX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0002031342</rptOwnerCik>
            <rptOwnerName>Luse Rebecca</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LB PHARMACEUTICALS INC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE PENNSYLVANIA PLAZA, SUITE 1025</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10119</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>false</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>15</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-09-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>22449</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2035-09-09</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>22449</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22449</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option award shall vest in three (3) equal annual installments on September 10, 2026, September 10, 2027 and September 10, 2028, subject to the Reporting Person's continuous service through such vesting date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Marc Panoff, Attorney-in-Fact</signatureName>
        <signatureDate>2025-09-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
