United States securities and exchange commission logo

                     December 20, 2023

       James Frates
       Chief Financial Officer
       Amylyx Pharmaceuticals, Inc.
       43 Thorndike St.
       Cambridge, MA 02141

                                                        Re: Amylyx
Pharmaceuticals, Inc.
                                                            Form 10-K for the
Fiscal Year Ended December 31, 2022
                                                            Filed March 13,
                                                            File Number

       Dear James Frates:

              We have completed our review of your filing. 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.


                     Division of Corporation Finance

                     Office of Life Sciences