Hormones Dominate Sports Doping and Account for Two-Thirds of All Violations

Hormone doping in sport is not merely a matter of fairness — it sits at the intersection of endocrinology, pharmacology, and public health. Understanding which hormones are abused, how they work, and how they are detected is essential for clinicians, sports medicine professionals, and anti-doping authorities alike.

This chapter, authored by Professor David Handelsman of the University of Sydney and published within the comprehensive Endotext reference resource, reviews the landscape of performance-enhancing hormone use in competitive sport. It covers the World Anti-Doping Agency framework, detection methodology, and the physiological basis for why certain hormones are exploited in specific sports.

The review identifies four pillars of athletic performance — skill, strength, endurance, and recovery — and maps each to specific doping strategies. Androgens (including natural steroids, synthetic steroidal compounds, and newer non-steroidal agents such as SARMs) are the most detected class of doping agents and are especially abused in power, combat, and collision sports due to their ability to increase muscle mass and strength. Erythropoiesis-stimulating agents and blood doping are the preferred tools for endurance athletes, as they increase oxygen-carrying capacity. Growth hormone and its secretagogues are used primarily to accelerate recovery from training and injury, although compelling evidence of ergogenic benefit remains elusive.

Hormones collectively account for approximately two-thirds of all anti-doping rule violations detected worldwide. While androgens remain relatively detectable, peptide hormones, growth hormone secretagogues, and autologous blood transfusions continue to evade reliable detection. Glucocorticoids, when used chronically, appear to impair muscle function; short-term high-dose use may blunt fatigue perception but is not prohibited. Thyroid hormone misuse is likely self-defeating, as hyperthyroidism promotes muscle wasting.

For clinicians, this review offers a practical framework for recognizing potential hormone doping in patients who are competitive athletes, understanding the physiological rationale behind each substance class, and appreciating the ongoing challenges in detection and regulation.