International Drug Names|
A14AA09 (WHO) |
|Chemical and physical data|
|3D model (Jmol)||
Norethandrolone (INN, BAN) (brand names Nilevar, Pronabol), also known as 17α-ethyl-19-nortestosterone or 17α-ethyl-19-norandrost-4-en-17β-ol-3-one, as well as ethylnandrolone or ethylnortestosterone, is a synthetic androgenic-anabolic steroid (AAS) and progestogen of the 17α-alkylated and 19-nortestosterone groups. It was synthesized at G. D. Searle & Company in 1953 and was originally studied as a progestin, along with norethisterone and noretynodrel, but ultimately was not marketed as such. In 1955, it was re-examined for testosterone-like activity and was found to have similar anabolic activity to testosterone but only one-sixteenth the androgenic potency.
Norethandrolone was introduced in the United States as an AAS in 1965 under the trade name Nilevar but was withdrawn from the market in the 1980s due to concerns of cholestatic jaundice. Norethandrolone is now only marketed in Australia, France, and Switzerland, and as with all 17α-alkylated oral steroids, long-term use in high doses may result in elevated liver enzymes and consequently cirrhosis. It is used in the treatment of muscle wasting, patients with severe burns, after severe trauma, and for certain forms of aplastic anemia.