trenbolone undecanoate trenbolone undecanoate trenbolone undecanoate, or trenbolone undecylate, is a synthetic and injected anabolic–androgenic steroid (aas) and a derivative of nandrolone (19-nortestosterone) which was never marketed. it is the c17β undecanoate (undecylate) ester and a long-acting prodrug of trenbolone. the drug was described by roussel uclaf in 1967 and was the first long-lasting ester of trenbolone to be developed. subsequently, trenbolone hexahydrobenzylcarbonate, a roughly equivalent compound, was developed and introduced for use in humans in 1980, though it was discontinued in 1997. trenbolone enanthate is another long-lasting ester of trenbolone. similarly to trenbolone undecanoate, it was never marketed, but it has been sold on the black market as a designer steroid for bodybuilders and athletes. trenbolone undecanoateclinical dataother namestrenbolone undecylate; estra-4,9,11-trien-17β-ol-3-one 17β-undecylateroutes ofadministrationintramuscular injectiondrug classandrogen; anabolic steroid; androgen ester; progestogenidentifiers iupac name phenanthren-17-yl] undecanoate chemical and physical dataformulac29h41o3molar mass437.644 g·mol−13d model (jsmol)interactive image smiles o(c(cccccccccc)=o)1cc()2()3ccc4=cc(ccc4=c3c=c21c)=o inchi inchi=1s/c29h41o3/c1-3-4-5-6-7-8-9-10-11-28(31)32-27-17-16-26-25-14-12-21-20-22(30)13-15-23(21)24(25)18-19-29(26,27)2/h18-20,25-26h,3-17h2,1-2h3/t25-,26+,29+/m1/s1key:dthsgqsbbrptmw-altzydrjsa-n