Tripeptide Gly-His-Lys is a hepatotropic immunosuppressor.

Ten intraperitoneal injections of tripeptide Gly-His-Lys in doses of 1.5, 5, 50, 150, and 450 mg/kg stimulated mitotic activity of hepatocytes and dose-dependently suppressed immune reactivity (number of antibody-producing cells and delayed-type hypersensitivity reaction).