AGREEMENT

EXHIBIT A

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13G need be filed with respect to the ownership by each of the undersigned of Common Stock of Trevi Therapeutics, Inc.

Date: April 18, 2022		XXXXXXX LIFE SCIENCES PUBLIC FUND, L.P.
		By: FHMLSP, L.P., its General Partner
		By: FHMLSP, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		FHMLSP, L.P.
		By: FHMLSP, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		FHMLSP, L.L.C.
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		XXXXXXX LIFE SCIENCES X, L.P.
		By: FHMLS X, L.P., its General Partner
		By: FHMLS X, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		FHMLS X, L.P.
		By: FHMLS X, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		FHMLS X, L.L.C.
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		XXXXXXX LIFE SCIENCES XI, L.P.
		By: FHMLS XI, L.P., its General Partner
		By: FHMLS XI, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer

Date: April 18, 0000		XXXXX X,X L.P.
		By: FHMLS XI, L.L.C., its General Partner
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		FHMLS XI, L.L.C.
		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, Chief Financial Officer
Date: April 18, 2022		By: *
		Xxxxx X. Xxxxxx
Date: April 18, 2022		By: *
		Xxxxxxx X. Xxxxx
Date: April 18, 2022		By: **
		Xxxxxx Xxx
Date: April 18, 2022		By: **
		Xxxxx Xxxxx
Date: April 18, 2022		By: ***
		Xxxxxx Xxxxx
Date: April 18, 2022		By: /s/ Xxxxx X. Xxxxxx
		Xxxxx X. Xxxxxx, as Attorney-in-Fact

* This Agreement was executed by Xxxxx X. Xxxxxx on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on March 29, 2016.

** This Agreement was executed by Xxxxx X. Xxxxxx on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which was filed with the SEC on August 16, 2021.

*** This Agreement was executed by Xxxxx X. Xxxxxx on behalf of the individual listed above pursuant to a Power of Attorney, a copy of which is included herewith as Exhibit B.