Trenbolone is a 3-oxo-Delta(4) steroid that is estra-4,9,11-triene carrying an oxo group at position 3 and a hydroxy group at position 17beta. It is a synthetic anabolic steroid used for muscle growth in livestock. It has a role as a plant metabolite and an endocrine disruptor. It is a 3-oxo-Delta(4) steroid, a 17beta-hydroxy steroid, a C18-steroid and an anabolic androgenic steroid.