Athletes who use GLP-1 medications just got another year of clarity. The World Anti-Doping Agency has confirmed that weight-loss drugs like Ozempic and Mounjaro will not appear on the 2027 Prohibited List, despite the agency actively studying whether they enhance performance and could be abused in sport.
The decision came out of Wada’s executive committee meeting this week, and while it keeps things unchanged for now, the reasoning Wada laid out is worth understanding - because the question is not whether GLP-1s are relevant to sport. The question is whether they cross the line from medication to performance enhancer, and Wada openly says it does not have that answer yet.
How a drug ends up banned
Wada does not ban substances on a whim. To move from the monitoring program to the prohibited list, a substance needs to meet at least two of three criteria: it can enhance sport performance, it poses a health risk to athletes, or it violates the spirit of sport.
Semaglutide, sold as Ozempic and Wegovy, has been on Wada’s monitoring list since 2024. Tirzepatide, branded Mounjaro, was added this year. The monitoring list is not a ban - it exists to track usage patterns and gather evidence on substances that might be heading somewhere. Being monitored is the anti-doping equivalent of being watched closely at the blackjack table: nothing happens yet, but everyone knows why you are there.
For 2027, neither compound met the two-of-three threshold with sufficient evidence, so both stay off the list.
What the Research Says
- Wada’s executive committee confirmed GLP-1 receptor agonists will not be added to the 2027 Prohibited List, per BBC Sport reporting of the decision.
- Semaglutide has been on Wada’s monitoring list since 2024; tirzepatide was added in 2026.
- Prohibition requires meeting two of three criteria: performance enhancement, health risk to athletes, or violation of the spirit of sport.
- Wada has started one study and is preparing a second examining the drugs’ effects in conditions designed to mimic high-level exercise, looking at whether pharmacological effects seen in patients with obesity also occur in non-obese, highly trained people.
- Under the usual timetable, a ban approved at the September 2027 executive committee meeting would take effect in January 2028.
Why Wada is moving slowly
Professor Olivier Rabin, Wada’s senior director for science and medicine, told BBC Sport the evidence picture is genuinely unresolved - and his reasoning is more interesting than a stock “more research needed” line.
The performance question cuts both ways. On one hand, dramatic weight loss with preserved (or even improved) relative power output is an obvious performance lever in weight-class sports, endurance events and anywhere power-to-weight decides outcomes. On the other hand, Rabin flagged that the side effects could work against athletes: nausea, fatigue, and loss of muscle mass. His line on that was blunt - if you are an athlete and you lose muscle mass, that may be very counterproductive for what you are trying to achieve.
That uncertainty is exactly why the studies exist. Wada wants to see whether the physiological changes documented in patients with obesity - appetite suppression, altered metabolism, body recomposition - show up in non-obese, highly trained athletes, where the baseline physiology is completely different. A drug that reshapes metabolism in someone with insulin resistance may do something quite different in a lean athlete at peak fitness. The studies are, in Rabin’s words, highly controlled and in very specific conditions, which is why they take time.
He also had a direct warning for athletes: be very careful using these drugs and never without medical advice and supervision, because the physiological shift is drastic enough to carry serious side effects - a notable statement from someone whose agency currently does not prohibit them.
The bigger context
The monitoring-list origins of this story say a lot about how quickly the landscape moved. Semaglutide landed on the monitoring list in 2024, barely two years after Ozempic became a household name. Tirzepatide followed within another two years. Anti-doping agencies usually track substances for much longer before considering action, and the speed here reflects both the sheer uptake of these drugs and the awkward questions they pose.
There is also the obvious cultural backdrop. Serena Williams publicly disclosed last year that she had used weight-loss medication while away from professional tennis, and the drugs are now common enough outside elite sport that Wada cannot pretend the question is hypothetical. The grey-market angle we cover constantly on this site - unapproved peptides sold online, counterfeit vials, the TGA’s crackdown - intersects with sport too. An athlete buying a “semaglutide” vial from an online vendor has no idea what is in it, which is both a health problem and, once a substance is monitored, potentially a career problem. The ABC reported in May that Australian sports drug testing was expanding partly because of the illicit peptide boom, with anti-doping authorities flagging GLP-1 agonists among the compounds of concern.
The timeline from here
Nothing changes for 2027. The realistic decision point for a ban is the September 2027 executive committee meeting, and under Wada’s usual timetable anything approved there would take effect in January 2028. That means roughly sixteen months of studies, monitoring data and argument before the next window.
Watch the muscle mass research closely in that period. The intersection of GLP-1s with lean-mass preservation drugs is one of the busiest corners of the pipeline - companies are running trials pairing GLP-1s with muscle-sparing agents precisely because the muscle loss is the biggest downside of aggressive weight loss. If those combinations mature, the performance calculus for athletes changes again, and Wada’s two-of-three assessment will be revisited with different inputs.
What it means in Australia
For the Australian research community, the practical takeaways are simple. If you compete in tested sport and you have a legitimate prescription for a GLP-1 medication, the current Wada position is that it is not prohibited - but “not prohibited” is not “unmonitored”, and the substance is on the radar precisely because of the questions above. Check with your federation’s anti-doping advisor before assuming anything, because supplements and grey-market products sold alongside peptides are a different risk category entirely, and testing positives for contaminated products are the athlete’s problem regardless of intent.
And if you are following the compounds from a research angle rather than a competitive one, the Wada deliberation is a useful stress test of what the evidence does and does not show. The same uncertainty that keeps the drugs off the list - unresolved performance effects, unresolved risk profile in lean populations - is the same uncertainty that surrounds casual use. Our semaglutide research page and tirzepatide page cover the published data on both compounds.
The Grey Highway Telegram group is where the community keeps track of this stuff as it lands, including the monitoring-list updates most coverage misses.
Sources
Source: BBC Sport (Tom Grundy and Emma Middleton), “Weight-loss drugs avoid Wada banned list for 2027”, September 10, 2026, via Yahoo News mirror. Includes quotes from Professor Olivier Rabin, Wada senior director for science and medicine.
Source: Wada 2027 Prohibited List and monitoring program context per the BBC Sport report: semaglutide monitored since 2024, tirzepatide added 2026, two-of-three prohibition criteria, studies underway, September 2027 decision timeline.
Disclaimer: This article is for educational and informational purposes only. It does not constitute medical advice, therapeutic recommendations, or endorsements of any compound. Grey Highway is a research-education community. We do not sell, supply, or promote the use of research compounds. Always consult a qualified healthcare professional regarding health decisions. For Australian regulatory information, visit the TGA website.