Routes of
administration Oral PubChem CID 261000 ChemSpider 229099 Molar mass 284.393 g/mol | CAS Number 965-93-5 IUPHAR/BPS 2857 Formula C19H24O2 Route Oral administration | |
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Synonyms Methyltrienolone, 17α-Methyltrenbolone; R-1881; RU-1881; NSC-92858; 17α-Methyl-19-nor-Δ-testosterone; 17α-Methylestra-4,9,11-trien-17β-ol-3-one | ||
Metribolone (INN) (developmental code names R-1881 (or RU-1881), NSC-92858), also known as methyltrienolone (or 17α-methyltrenbolone), as well as 17α-methyl-19-nor-Δ9,11-testosterone or 17α-methyl-19-norandrosta-4,9,11-triene-17β-ol-3-one, is a highly potent, orally active, non-aromatizable anabolic-androgenic steroid (AAS) of the 19-nortestosterone and 17α-alkylated groups which was never marketed for clinical use but has been used in scientific research as a photoaffinity label for the androgen receptor (AR) and in AR ligand binding assays. It is the 17α-methylated derivative of trenbolone (trienolone), and is a similarly potent AAS, but has a high potential for hepatotoxicity similarly to other 17α-alkylated AAS. Metribolone binds with high affinity not only to the AR but also to the progesterone receptor (PR), and binds to the glucocorticoid receptor (GR) as well. It is said to be the most potent AAS.
Eleven members of the Greek national weightlifting team and 4 Greek track and field athletes tested positive with methyltrienolone prior to the 2008 Beijing Olympic Games.