Trenbolone enanthate is an injectable form of the strong anabolic steroid trenbolone. Given the use of an enanthate ester, this drug will exhibit virtually identical pharmacokinetics to testosterone enanthate, providing a peak release of its steroid within the first several days after injection, followed by declining levels for approximately 2 weeks. The base steroid here (trenbolone) is a derivative of nandrolone, and exhibits strong anabolic and androgenic properties. On a milligram for milligram basis it is considerably more potent than testosterone as both an anabolic and androgenic agent, though it does carry a more favorable balance (toward anabolism). Trenbolone is also unable to convert to estrogen, however it does exhibit notable progestational activity, which may mimic estrogenic side effects given the right physiological conditions. Trenbolone enanthate is virtually interchangeable with Parabolan (trenbolone hexahydrobenzylcarbonate), capable of promoting strong gains in lean muscle mass, often with an accompanying increase in relative hardness and definition. 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 slows its metabolism. The trenbolone here is modified with an enanthate ester at the 17-beta hydroxyl group, so that the free steroid is released more slowly from the area of injection.