Norbolethone
First identified in a competitive cyclist's urine in 2002 by WADA — the first 'designer steroid' discovered in the modern era of doping. Originally synthesized by Wyeth in the 1960s but never marketed. Patrick Arnold (BALCO) reportedly distributed it before THG gained notoriety. Exceptionally high anabolic:androgenic ratio.
Mechanism of Action
19-nor derivative with both 13β and 17α-ethyl modifications. Does not aromatize significantly. High AR binding selectivity for anabolic tissues. Very low androgenic activity explains the extremely low detection likelihood in early screening. The 13β-ethyl modification substantially alters receptor binding kinetics.
Typical Dosing
⚠ Warning Flags
- •Never approved for human use — no clinical safety data
- •BALCO-era designer doping agent
- •WADA prohibited
Effect Profile
Side Effect Profile
Research Studies
Norbolethone: an anabolic steroid never marketed and first identified in a urine sample of a competitive athlete
Catlin DH, et al. · 2002
First published identification of norbolethone as a doping agent — mass spectrometric analysis of a cyclist's urine revealed its metabolites, documenting its pharmaceutical history (Wyeth 1966) and its use as an undetectable designer steroid.