Testosterone undecanoate, sold under the brand names Andriol and Aveed among others, is an androgen and anabolic steroid (AAS) .It can promote male growth, male secondary sex characteristics and the development of testis and accessory gonad structures. Promote protein synthesis and reduce breakdown, enhance immune function, promote bone growth. Promote erythropoiesis, feedback inhibition of gonadotropin secretion, inhibition of estrogen secretion.