<SEC-DOCUMENT>0001628280-23-039898.txt : 20231122
<SEC-HEADER>0001628280-23-039898.hdr.sgml : 20231122
<ACCEPTANCE-DATETIME>20231122171826
ACCESSION NUMBER:		0001628280-23-039898
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20231120
FILED AS OF DATE:		20231122
DATE AS OF CHANGE:		20231122

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Felsch Robert Ora
		CENTRAL INDEX KEY:			0001917819

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36485
		FILM NUMBER:		231434450

	MAIL ADDRESS:	
		STREET 1:		C/O ARDELYX, INC.
		STREET 2:		34175 ARDENWOOD BLVD.
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94555

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARDELYX, INC.
		CENTRAL INDEX KEY:			0001437402
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		34175 ARDENWOOD BLVD.
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94555
		BUSINESS PHONE:		510-745-7047

	MAIL ADDRESS:	
		STREET 1:		34175 ARDENWOOD BLVD.
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94555

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NTERYX INC
		DATE OF NAME CHANGE:	20080611
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1700691493.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-11-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001437402</issuerCik>
        <issuerName>ARDELYX, INC.</issuerName>
        <issuerTradingSymbol>ARDX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001917819</rptOwnerCik>
            <rptOwnerName>Felsch Robert Ora</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ARDELYX, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>400 FIFTH AVENUE, SUITE 210</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02451</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>See Remarks</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-11-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1044</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.3622</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>117066</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Pursuant to an automatic sell-to-cover imposed by the terms of the initial grant of the restricted stock units (&quot;RSUs&quot;) awards, the shares were sold upon the vesting of the RSUs solely to cover applicable withholding taxes.</footnote>
        <footnote id="F2">Reflects the adjusted total which includes the purchase of 3,000 shares under the Ardelyx Employee Stock Purchase Plan in August 2023.</footnote>
    </footnotes>

    <remarks>SVP Finance and Chief Accounting Officer</remarks>

    <ownerSignature>
        <signatureName>/s/ Elizabeth Grammer, Attorney-in-Fact for Robert Ora Felsch</signatureName>
        <signatureDate>2023-11-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
