Methyltrienolone

Metribolone (developmental code name R1881), also known as methyltrienolone, is a synthetic and orally active anabolic–androgenic steroid (AAS) and a 17α-alkylated nandrolone (19-nortestosterone) derivative which was never marketed for medical use but has been widely used in scientific research as a hot ligand in androgen receptor (AR) ligand binding assays (LBAs) and as a photoaffinity label for the AR. More precisely, metribolone is the 17α-methylated derivative of trenbolone.