Administration of Clomiphene: Short and Long Term Metabolism in an Anti-Doping Setting

Clomiphene, pharmaceutically prepared as clomiphene citrate, is a selective estrogen receptor modulator (SERM) with a therapeutic indication to treat female infertility. Though FDA-approved only for use in women, clomiphene is often prescribed off-label to males to treat male infertility and secondary hypogonadism due to its ability to increase serum testosterone levels. Numerous clinical studies have documented both the effectiveness for these indications and safety of clomiphene administration in males. Increasing the concentration of circulating testosterone can have additional effects, including the enhancement of performance in sports. As such, clomiphene is already abused by athletes in several sporting disciplines, including mixed martial arts, cycling, and bodybuilding. Therefore, clomiphene is a prohibited substance under the World Anti-Doping Agency code . Though the parent compound and metabolites of clomiphene are directly detectable in routine anti-doping screening, the urinary detection window and the effect of clomiphene administration on other anti-doping markers are unknown and thus the foci of this study.

Inclusion criteria

• Active males who engage in regular exercise between the ages of 18 and 40 on the day of enrollment

• For this study, regular exercise is defined as: physical activity resulting in an increased heart rate for at least 30 minutes per day, 4-5 days per week.

Exclusion criteria

• Individuals outside of the described age range on the day of enrollment
• Individuals who are in a Registered Testing Pool for anti-doping purposes, or individuals who for any reason could be subject to doping control testing
• Individuals who are unwilling or unable to provide blood or urine samples
• Individuals who do not actively exercise
• Individuals with any history of cancer, cardiovascular disease, endocrine abnormalities, infertility, hypoandrogenism, renal disease, hepatic disease, neurologic disease, or any psychiatric history
• Individuals who have previously used anabolic steroids, selective estrogen receptor modulators (SERMs), selective androgen receptor modulators (SARMs), or who are currently using any substances included on the WADA Prohibited List
• History of venous thromboembolic disease (i.e. deep vein thrombosis or pulmonary embolism)
• History of untreated cataracts
• History of intracranial lesions such as pituitary tumors
• Transaminase elevation greater than 3 times the upper limit of normal (ULN)
• Moderate or heavy alcohol intake