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 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. It 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. This steroid is highly valued for its ability to increase muscle hardness, definition, and raw strength, without unwanted water retention and fat mass gains.