Detectability of oxandrolone, metandienone, clostebol and dehydrochloromethyltestosterone in urine after transdermal application

Situations of both, intentional and inadvertent or accidental doping, necessitate consideration in today's doping controls, especially in the light of the substantial consequences that athletes are facing in case of so-called adverse analytical findings. The aim of this study was to investigate, whether a transdermal uptake of doping substances would be possible. In addition to the period of detectability of the particular substances or respective characteristic metabolites, the possibility of deducing the route of administration by metabolite patterns was also assessed. Twelve male subjects were included in the study. Four common anabolic androgenic steroids (AAS) were dissolved in dimethylsulfoxide to facilitate transdermal administration on different skin regions. One half of the test persons received only oxandrolone (17α-methyl-2-oxa-4,5α-dihydrotestosterone), and the other half were applied a mixture of oxandrolone, metandienone (17β-hydroxy-17α-methylandrosta-1,4-dien-3-one), clostebol (4-chlorotestosterone-17β-acetate) and dehydrochloromethyltestosterone (DHCMT). Urine samples were collected 1 h, 6 h and one sample per day for the next 14 consecutive days. Measurements were conducted on a tandem-gas chromatography–mass spectrometry (GC-MS/MS) or tandem-liquid chromatography–MS/MS (LC-MS/MS) system. Substance findings were obtained at least 1 day after application on nearly all skin locations. The results indicated inter-individual variability in detection windows, also varying between the different analytes and possible impact of skin location and skin thickness, respectively. Nevertheless, a rapid and rather long detectability of all substances (or respective metabolites) was given, in some cases within hours after administration and for up to 10–14 days. Hence, the transdermal application or exposure to the investigated AAS is a plausible scenario that warrants consideration in anti-doping.