Testosterone diacetate, or testosterone 3ò,17ò-diacetate, also known as 4-androstenediol diacetate, as well as androst-4-ene-3ò,17ò-diol 3ò,17ò-diacetate, is a synthetic anabolic-androgenic steroid and an androgen ester which was never marketed. It is the 3ò,17ò-diacetate diester of testosterone (androst-4-en-17ò-ol-3-one), or, more accurately, of 4-androstenediol (androst-4-ene-3ò,17ò-diol).