GLP-1 (glucagon-like peptide-1) class medications, such as Novo Nordisk’s Wegovy and Eli Lilly’s Mounjaro, are increasingly recognized for benefits extending far beyond weight loss and blood sugar management. By mimicking appetite-regulating hormones to enhance satiety, these treatments have been shown to reduce systemic inflammation, improve metabolic health, and lower the long-term risk of cardiovascular disease, kidney disease, and dementia. However, as their wide-ranging physiological impacts become clearer, questions are emerging over whether their use by professional athletes constitutes sports doping.
The debate intensified after tennis legend Serena Williams disclosed her use of Mounjaro during an appearance on an Oprah Winfrey podcast. Williams revealed that despite grueling eight-hour daily workouts throughout her career, weight management remained an elusive challenge—one that Mounjaro finally helped her address. While supporters viewed her disclosure as a transparent account of personal health management, critics questioned whether pharmaceutical assistance for weight control compromises athletic fairness.
Criteria for Banned Substances
Currently, no major sports authority bans GLP-1 medications. To be placed on the World Anti-Doping Agency (WADA) prohibited list, a substance must generally meet at least two of three criteria: performance enhancement, a real or potential health risk to the athlete, or a violation of the spirit of sport. To date, there is no direct scientific evidence showing that Wegovy or Mounjaro meets these thresholds for banned designation.
Concerns Over Weight-Class Advantages and Recovery
Nevertheless, medical specialists caution that GLP-1 drugs could create uneven playing fields in specific athletic disciplines. Professor Massimo Mapelli of the Monzino Cardiology Center in Italy highlighted the potential impact on weight-class sports, such as combat sports and weightlifting, where strength and leverage are closely tied to body mass. Mapelli noted that if an athlete uses medication to rapidly shed weight and move down a weight class, it could disrupt fair competition by allowing them to face smaller opponents while retaining structural muscle advantages.
Beyond weight management, researchers point to potential physiological benefits. Dr. Daniel Drucker, an endocrinology researcher at the University of Toronto, noted that GLP-1 drugs exert systemic effects, including reducing inflammation and enhancing blood flow to muscles. While formal clinical trials in elite athletes have not been conducted, Drucker suggested it is difficult to rule out potential benefits for post-exercise recovery.
For now, WADA maintains a cautious stance, keeping GLP-1 class drugs on its official monitoring list to track patterns of use and evaluate any potential performance-enhancing effects as research evolves.
