Weight-loss drugs such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro) will not be added to the World Anti-Doping Agency's (Wada) list of prohibited substances for athletes in 2027. Both drugs are currently on Wada's monitoring list, having been added in 2024 and 2023 respectively.
Wada uses a three-part criterion to determine if a substance should be moved from monitoring to the prohibited list: whether it can enhance athletic performance, poses a health risk to athletes, or violates the spirit of sport. The agency is conducting studies to evaluate the effects of these drugs under conditions that mimic high-level exercise.
"It's still going to take us a little bit of time to collect all this information, because they are highly controlled studies in very specific conditions," said a Wada representative. The research aims to ascertain if the physiological impacts observed in obese patients would also occur in non-obese, highly trained individuals.
Potential side effects, including nausea, fatigue, and muscle mass loss, could counteract any perceived performance benefits for athletes. "If you're an athlete and you lose muscle mass, that may be very counterproductive for what you're trying to achieve," the representative noted, indicating the complexity of the decision.
Any changes to the prohibited list approved by Wada's executive committee in September would typically take effect in January of the following year, meaning a potential inclusion in 2028 at the earliest, should the drugs meet the necessary criteria after ongoing research.