Preparing a hydrolyzate of viscera of marine animals comprises (a) mixing co-products of marine animals, (b) heating the resulting mixture at 30-65[deg] C, (c) adjusting the pH of the mixture to 1-8, (d) enzymatically hydrolyzing the obtained mixture for a duration of 1-8 hours, (e) heating the resulting hydrolyzate at 75-150[deg] C, and (f) cooling the resulting hydrolyzate. An independent claim is included for the hydrolyzate of viscera of marine animals obtained by the above process. ACTIVITY : Anabolic; Antilipemic; Muscular-Gen.; Antiinflammatory. MECHANISM OF ACTION : None given.