Trenbolone acetate is an injectable (generally) anabolic steroid derived from nandrolone. Its activity is quite removed from its structural parent, however, such that direct comparisons between the two are difficult. Trenbolone is a non-estrogenic steroid, and is considerably more anabolic and androgenic than nandrolone on a milligram for milligram basis. In appearance, it is much more commonly compared to a stronger androgen such as drostanolone, than it is to nandrolone. lt is also estimated to display about three times more androgenic potency than testosterone, making it one of the strongest injectable anabolic steroids ever commercially manufactured. Among athletes, this steroid is highly valued for its ability to increase muscle hardness, definition, and raw strength, without unwanted water retention and fat mass gains. It is considered a drug of choice for contest bodybuilders, yet remains very popular with recreational users simply looking to refine their physiques. Trenbolone is a modified form of nandrolone. It differs by the introduction of double bonds at carbons 9 and 11, which inhibit aromatization (9-ene), increase androgenbinding affinity, and slow its metabolism. The resulting steroid is significantly more potent as both an anabolic and an androgen than its nandrolone base. Trenbolone acetate contains trenbolone modified with the addition of carboxylic acid ester (acetic acid) at the 17-beta hydroxyl group, so that the free steroid is released more slowly from the area of injection.