In 1999, France passed a law against doping, the so-called Loi Buffet. This law was designated to protect athletes against doping consequences, particularly after long-term abuse. In 2001, this law was implemented with its practical aspects. Among them, hair sampling to document chronic exposure was considered as a valid procedure.

Drug administration can be tracked by hair analysis for months or even years and thus, offers the possibility of determinating long-term drug exposure (1). Corticosteroids are known to have numerous side effects. During the treatment of specific deseases, these compounds are allowed in urine for a short period of time, but in the case of doping practices, it may be of interest to evaluate chronic administration of corti- costeroids. Scientific literature contains only a few reports on the identification of corticosteroids in hair (2–4), but these substances can be added to the list of xenobiotics incorporated into hair. However, the interpretation of the results with unknown dosages of corticosteroids appears very difficult. Among the problems associated with the use of hair in doping control, the unknown dose-concentration relationship can lead to controversies about the potential applications of the specimen (5). To evaluate the existance of a such a correlation, this article reports the identification and quantitation of prednisone in human hair of patients treated with Cortancyl®.