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                          January 23, 2023

       Michael Raab
       President & Chief Executive Officer
       Ardelyx, Inc.
       400 Fifth Avenue, Suite 210
       Waltham, MA 02451

                                                        Re: Ardelyx, Inc.
                                                            Registration
Statement on Form S-3
                                                            Filed January 19,
2023
                                                            File No. 333-269297

       Dear Michael Raab:

              This is to advise you that we have not reviewed and will not
review your registration
       statement.

               Please refer to Rules 460 and 461 regarding requests for
acceleration. We remind you
       that the company and its management are responsible for the accuracy and
adequacy of their
       disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

                                                        Please contact Tyler
Howes at 202-551-3370 with any questions.




                          Sincerely,


                          Division of Corporation Finance

                          Office of Life Sciences
       cc:                                              Mark V. Roeder, Esq.