Trenbolone undecanoate, or trenbolone undecylate, is a synthetic injected anabolic–androgenic steroid (AAS) that is 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 researchers at 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 approved in Europe for human medical use in 1980, though it was discontinued in 1997. Trenbolone enanthate is another long-lasting ester of trenbolone. Similarly to trenbolone undecanoate, it was never approved for human use, but is sold on the black market for use by bodybuilders and athletes.
See also List of androgen esters § Trenbolone esters
References
Further reading Yarrow JF, McCoy SC, Borst SE (2010). "Tissue selectivity and potential clinical applications of trenbolone (17beta-hydroxyestra-4,9,11-trien-3-one): A potent anabolic steroid with reduced androgenic and estrogenic activity". Steroids. 75 (6): 377–89. doi:10.1016/j.steroids.2010.01.019. PMID 20138077. S2CID 205253265.


