POWER OF ATTORNEY
  Know all by these presents, that the undersigned hereby constitutes and
appoints each of Raj Kannan, John Doyle, Lee Giguere and Drew Enamait, signing
singly, the undersigneds true and lawful attorney-in-fact to:
(1)  execute for and on behalf of the undersigned, in the undersigneds capacity
as an officer and/or director of Chiasma, Inc. (the Company), Forms 3, 4 and 5
and amendments thereto in accordance with Section 16(a) of the Securities
Exchange Act of 1934, as amended, and the rules thereunder;
(2)  do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form 3, 4 or 5
and amendments thereto and timely file such form with the United States
Securities and Exchange Commission and any stock exchange or similar authority;
and
(3)  take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in-facts discretion.
   The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-facts substitute or substitutes, shall lawfully do or cause to be
done by virtue of this Power of Attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigneds responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934, as amended. The
undersigned hereby agrees to indemnify the attorney-in-fact and the Company from
and against any demand, damage, loss, cost or expense arising from any false or
misleading information provided by the undersigned to the attorney-in-fact.
        This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigneds holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.  This Power of Attorney may be filed with the
United States Securities and Exchange Commission as a confirming statement of
the authority granted herein. This Power of Attorney supersedes any prior power
of attorney in connection with the undersigneds capacity as an officer and/or
director of the Company.  This Power of Attorney shall expire as to any
individual attorney-in-fact if such attorney-in-fact ceases to be an executive
officer of the Company.
        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of February 5, 2021.

/s/ David Stack
David Stack