<?xml version="1.0" encoding="UTF-8"?><edgarSubmission xmlns="http://www.sec.gov/edgar/ownership" xmlns:ns2="http://www.sec.gov/edgar/common">
    <headerData>
        <submissionType>144</submissionType>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001321402</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>



        </filerInfo>
    </headerData>
    <formData>
        <issuerInfo>
            <issuerCik>0001437402</issuerCik>
            <issuerName>ARDELYX INC</issuerName>
            <secFileNumber>001-36485</secFileNumber>
            <issuerAddress>
                <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                <ns2:city>Waltham</ns2:city>
                <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                <ns2:zipCode>02451</ns2:zipCode>
            </issuerAddress>
            <issuerContactPhone>5107451700</issuerContactPhone>
            <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>MICHAEL RAAB</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
            <relationshipsToIssuer>
                <relationshipToIssuer>Director</relationshipToIssuer>
                <relationshipToIssuer>Officer</relationshipToIssuer>
            </relationshipsToIssuer>
        </issuerInfo>
        <securitiesInformation>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <brokerOrMarketmakerDetails>
                <name>Morgan Stanley Smith Barney LLC Executive Financial Services</name>
                <address>
                    <ns2:street1>1 New York Plaza</ns2:street1>
                    <ns2:street2>8th Floor</ns2:street2>
                    <ns2:city>New York</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10004</ns2:zipCode>
                </address>
            </brokerOrMarketmakerDetails>
            <noOfUnitsSold>125000</noOfUnitsSold>
            <aggregateMarketValue>683750.00</aggregateMarketValue>
            <noOfUnitsOutstanding>239255212</noOfUnitsOutstanding>
            <approxSaleDate>05/02/2025</approxSaleDate>
            <securitiesExchangeName>NASDAQ</securitiesExchangeName>
        </securitiesInformation>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>05/02/2025</acquiredDate>
            <natureOfAcquisitionTransaction>Exercise of Stock Options</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>62500</amountOfSecuritiesAcquired>
            <paymentDate>05/02/2025</paymentDate>
            <natureOfPayment>Cash</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>09/14/2020</acquiredDate>
            <natureOfAcquisitionTransaction>Performance Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>10330</amountOfSecuritiesAcquired>
            <paymentDate>09/14/2020</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <securitiesToBeSold>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <acquiredDate>02/19/2024</acquiredDate>
            <natureOfAcquisitionTransaction>Restricted Stock Units</natureOfAcquisitionTransaction>
            <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
            <isGiftTransaction>N</isGiftTransaction>
            <amountOfSecuritiesAcquired>52170</amountOfSecuritiesAcquired>
            <paymentDate>02/19/2024</paymentDate>
            <natureOfPayment>N/A</natureOfPayment>
        </securitiesToBeSold>
        <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>04/04/2025</saleDate>
            <amountOfSecuritiesSold>41666</amountOfSecuritiesSold>
            <grossProceeds>191151.11</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>10b5-1 Sales for MICHAEL RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>03/07/2025</saleDate>
            <amountOfSecuritiesSold>41668</amountOfSecuritiesSold>
            <grossProceeds>223198.81</grossProceeds>
        </securitiesSoldInPast3Months>
        <securitiesSoldInPast3Months>
            <sellerDetails>
                <name>MICHAEL RAAB</name>
                <address>
                    <ns2:street1>400 Fifth Avenue Suite 210</ns2:street1>
                    <ns2:city>Waltham</ns2:city>
                    <ns2:stateOrCountry>MA</ns2:stateOrCountry>
                    <ns2:zipCode>02451</ns2:zipCode>
                </address>
            </sellerDetails>
            <securitiesClassTitle>Common</securitiesClassTitle>
            <saleDate>02/20/2025</saleDate>
            <amountOfSecuritiesSold>22964</amountOfSecuritiesSold>
            <grossProceeds>129124.28</grossProceeds>
        </securitiesSoldInPast3Months>
        <remarks>The securities to be sold will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment will be the dates of exercise/sale.
The securities to be sold were acquired upon the vesting of restricted stock units during the period of 2/19/2024 through 5/19/2024.
</remarks>
        <noticeSignature>
            <noticeDate>05/02/2025</noticeDate>
            <planAdoptionDates>
                <planAdoptionDate>09/04/2024</planAdoptionDate>
            </planAdoptionDates>
            <signature>/s/ Michael Raab</signature>
        </noticeSignature>
    </formData>
</edgarSubmission>
[{"type": "144", "sequence": "1", "filename": "primary_doc.xml", "secsgml_size_bytes": 7002}]
144
0001321402
XXXXXXXX
LIVE
0001437402
ARDELYX INC
001-36485
400 Fifth Avenue Suite 210
Waltham
MA
02451
5107451700
MICHAEL RAAB
Director
Officer
Common
Morgan Stanley Smith Barney LLC Executive Financial Services
1 New York Plaza
8th Floor
New York
NY
10004
125000
683750.00
239255212
05/02/2025
NASDAQ
Common
05/02/2025
Exercise of Stock Options
Issuer
N
62500
05/02/2025
Cash
Common
09/14/2020
Performance Stock Units
Issuer
N
10330
09/14/2020
N/A
Common
02/19/2024
Restricted Stock Units
Issuer
N
52170
02/19/2024
N/A
N
10b5-1 Sales for MICHAEL RAAB
400 Fifth Avenue Suite 210
Waltham
MA
02451
Common
04/04/2025
41666
191151.11
10b5-1 Sales for MICHAEL RAAB
400 Fifth Avenue Suite 210
Waltham
MA
02451
Common
03/07/2025
41668
223198.81
MICHAEL RAAB
400 Fifth Avenue Suite 210
Waltham
MA
02451
Common
02/20/2025
22964
129124.28
The securities to be sold will be received upon the exercise of stock options over the next three months. The dates of acquisition and payment will be the dates of exercise/sale.
The securities to be sold were acquired upon the vesting of restricted stock units during the period of 2/19/2024 through 5/19/2024.
05/02/2025
09/04/2024
/s/ Michael Raab