Epitestosterone

Epitestosterone

File:Epitestosterone.gif
Identifiers
IUPAC name 17-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17- dodecahydrocyclopenta[a]phenanthren-3-one
CAS Number	481-30-1
CompTox Dashboard (EPA)	DTXSID8022329
ECHA InfoCard	100.169.813
Chemical and physical data
Formula	C19H28O2
Molar mass	288.42

Epitestosterone is a natural steroid, an inactive isomer of the hormone testosterone. Epitestosterone is believed to form in a similar way to testosterone, however, the exact site of its formation is unknown. Furthermore, exogenous administration of testosterone does not affect levels of epistestosterone in the body.

As a result, tests to determine the ratio of testosterone to epitestosterone in urine are used to find athletes who are doping. A normal healthy person has a ratio of about 1:1 testosterone to epitestosterone (T/E ratio) in their urine.

Although epitestosterone has not been shown to enhance athletic performance, administration of epistestosterone can be used to mask a high level of testosterone if the standard T/E ratio test is used. As such, epitestosterone is banned by many sporting authorities as a masking agent for testosterone.

Urine test taken from Floyd Landis, winner of the 2006 Tour de France showed "an unusual level of testosterone/epitestosterone," in violation of the 4:1 limit imposed by the race organizers, suggesting doping, though this may have been caused by a low epitestosterone level rather than an artificially elevated testosterone level. Landis has also claimed that an elevated testosterone level could be related to his hypothyroidism.

External links

Landis Fails Drug Test After Triumph in Tour de France

Institute of Endocrinology Abstract on Epistestosterone