Genetic variation in androgen disposition: implications in clinical medicine including testosterone abuse

Background: Testosterone replacement therapy in hypogonadal men has been used for > 60 years. The use of testosterone substitution is continuously growing and is given to aging men to improve the quality of life. Because testosterone use is associated with muscle strength enhancing effects, it has become a popular drug to abuse. Doping with anabolic steroids, such as testosterone, is a severe challenge to the vision, moral and ethics in sports and has also become a significant and increasing problem in society. Objective: The primary aim of this review is to summarize and discuss the contribution of genetic components to inter-individual variation in androgen disposition. Conclusion: Genetic variation has a large impact on androgen disposition. This variation is of the utmost importance for the interpretation of doping test results and may modulate the effects of testosterone replacement therapy and testosterone doping.