Distribution of Clomiphene and Its Metabolites in Antidoping Samples—A 3‐Year Perspective

Clomiphene use substantially enhances endogenous testosterone production in males. Consequently, it is included under Section 4.2 of the World Anti-Doping Agency (WADA) Prohibited List and prohibited at all times (in and out of competition). Previous research has highlighted the prolonged excretion and detection windows for clomiphene and its metabolites after cessation of use. In addition to therapeutic use in humans, clomiphene may also be used to increase egg production in laying hens. Accordingly, clomiphene and/or its metabolites may also be detected in human urine after consumption of eggs or meat from treated poultry. To address some of these complexities, WADA has issued targeted guidance in Technical Letter TL26, mandating a minimum reporting level for clomiphene. This short communication evaluates results from clomiphene findings in 325 urine samples over the past 3 years and examines how reporting would be affected by the criteria outlined in TL26.