Power of Attorney for Michael Donovan

This filing details a Limited Power of Attorney granted by Michael Donovan, an officer, director, and beneficial owner of Collegium Pharmaceutical, Inc., to Vikram Karnani, Colleen Tupper, and David Dieter. The attorneys-in-fact are authorized to execute and file Forms 3, 4, and 5, as well as any necessary amendments, with the SEC and stock exchanges on behalf of Mr. Donovan. This authorization is in accordance with Section 16(a) of the Securities Exchange Act of 1934. The attorneys-in-fact have the discretion to take any action deemed beneficial, in the best interest, or legally required. The power of attorney remains in effect until revoked in writing. The document was signed by Michael Donovan on May 15, 2026.