Athletes will remain permitted to use weight-loss drugs such as Ozempic and Mounjaro under World Anti-Doping Agency rules in 2027, but WADA is continuing to monitor the medications amid concerns about possible performance benefits, health risks and misuse in elite sport.

The rapidly growing use of GLP-1 weight-loss medications has created a new challenge for global anti-doping authorities.

The World Anti-Doping Agency, better known as WADA, has confirmed that GLP-1 receptor agonists will not be added to its prohibited substances list for 2027.

That means athletes will not automatically commit an anti-doping violation simply by using medicines such as semaglutide or tirzepatide under the 2027 rules.

However, that should not be interpreted as WADA declaring the drugs irrelevant to sport.

Quite the opposite.

The substances will remain on WADA’s monitoring programme while scientists investigate whether they could offer athletes an unfair competitive advantage or create significant health risks.

The next phase of research could eventually determine whether some of these drugs should be banned in future seasons.

What Are GLP-1 Weight-Loss Drugs?

GLP-1 receptor agonists are medicines that can influence appetite, blood sugar regulation and digestion.

They have become increasingly prominent because of their effectiveness in helping some people lose weight.

Among the most widely recognised names are:

• Ozempic
• Wegovy
• Mounjaro

Semaglutide is associated with products including Ozempic and Wegovy, while tirzepatide is commonly marketed under the Mounjaro brand.

Their rapid rise outside elite sport has inevitably led anti-doping officials to examine whether athletes could also begin using them strategically.

Weight-Loss Drugs Are Not Banned in Sport for 2027

WADA reviews its prohibited list every year.

Following a meeting of its executive committee, the agency decided there was not yet enough evidence to move GLP-1 drugs from monitoring status to the prohibited list.

The 2027 rules will take effect in January.

For athletes, the key distinction is important.

A substance appearing on WADA’s monitoring list is not the same as it being prohibited.

Monitoring means the organisation is gathering information about patterns of use and studying whether the substance could eventually meet the criteria required for a ban.

Why Is WADA Monitoring Ozempic and Similar Drugs?

The concern is not simply that these medications can reduce body weight.

In elite sport, even small changes in body composition can potentially influence performance.

That makes GLP-1 drugs particularly interesting to anti-doping authorities.

WADA wants to understand whether the physiological effects seen in patients receiving the drugs for medical reasons could also occur in highly trained athletes who are not obese.

That distinction matters.

A medicine may behave differently and produce different advantages or disadvantages — depending on the health and physical condition of the person taking it.

What Does a Drug Need to Be Banned by WADA?

A substance generally needs to satisfy at least two of three criteria before it can be added to WADA’s prohibited list.

Those criteria concern whether the substance:

1. Has the potential to enhance sporting performance.
2. Represents an actual or potential health risk to athletes.
3. Violates what WADA considers the spirit of sport.

The current uncertainty around GLP-1 drugs is therefore significant.

Their ability to produce weight loss is well known.

What remains less clear is whether that translates into a meaningful sporting advantage for already lean, highly trained athletes.

WADA Is Conducting Controlled Studies

WADA has already started one research project and is preparing another to examine GLP-1 medications under conditions designed to resemble high-level exercise.

The studies are intended to answer an important question:

What happens when these drugs are used by trained athletes rather than the patient groups in which they are typically studied?

WADA science and medicine director Professor Olivier Rabin has indicated that reaching reliable conclusions will take time because the research must be carefully controlled.

The results could influence future anti-doping policy.

Could Weight Loss Improve Athletic Performance?

In some sports, being lighter can theoretically provide an advantage.

An athlete who reduces body weight while maintaining strength and power may improve their power-to-weight ratio.

That concept is particularly important in endurance sports and events where athletes must move their own body mass over long distances or steep terrain.

Weight is also crucial in sports with strict competition categories.

That creates an obvious question.

Could an athlete use a GLP-1 medication to make weight more easily while avoiding the harsher effects of conventional rapid weight-loss practices?

It is one of the scenarios anti-doping authorities must now examine.

Boxing and Wrestling Could Be Particularly Vulnerable

Weight-category sports immediately stand out as potential areas of misuse.

Boxers and wrestlers frequently need to meet strict weight limits before competition.

Traditionally, athletes may attempt to reduce weight through combinations of dieting, increased training, water manipulation and other strategies.

Some of these methods can already pose health risks.

A medication capable of suppressing appetite and contributing to significant weight loss could therefore appear attractive.

Even when an athlete has no underlying medical need for it.

Jockeys Could Also Be Interested

Horse racing presents another obvious example.

Jockeys operate under demanding weight requirements and often need to carefully manage their body mass.

WADA has highlighted weight control as a relevant consideration in sports extending beyond traditional weight-class events.

A drug that allows an athlete to maintain a lower weight could theoretically become attractive even when there is no direct weight category.

Cyclists and Long-Distance Runners May Also Be Relevant

Endurance sport is another area attracting attention.

For elite cyclists, body weight can significantly influence climbing performance.

For long-distance runners, carrying less unnecessary mass may also be perceived as advantageous.

That does not mean GLP-1 medications have been proven to enhance performance in these athletes.

They have not.

But the potential incentive to experiment with them is one reason WADA continues to investigate.

The Power-to-Weight Question

Cycling provides perhaps the clearest example.

An athlete’s raw power matters.

But so does how much body mass that power must move.

If weight falls while power remains stable, performance could theoretically improve in some circumstances.

The problem is that GLP-1-related weight loss may not exclusively involve body fat.

Muscle can also be lost.

And for an elite athlete, that could completely change the calculation.

Muscle Loss Could Make the Drugs Counterproductive

One of WADA’s biggest concerns is that the perceived benefits of weight-loss medications may be offset by their side effects.

Professor Rabin has specifically highlighted the potential loss of muscle mass.

That matters because athletes depend heavily on preserving lean tissue.

Losing weight may seem beneficial.

Losing strength at the same time may not be.

For a sprinter, weightlifter, footballer, boxer, cyclist or almost any other elite athlete, muscle function is fundamental to performance.

The result could therefore be paradoxical.

A drug used with the intention of improving sporting performance could ultimately make the athlete worse.

Nausea and Fatigue Are Also Important

Potential side effects such as nausea and fatigue are equally relevant.

Elite training requires athletes to maintain:

• Adequate nutrition
• Hydration
• Recovery
• Muscle repair
• Energy availability

A medication that significantly suppresses appetite or causes gastrointestinal symptoms could interfere with those demands.

For an ordinary patient, reduced appetite may contribute to the intended therapeutic effect.

For an athlete training intensely for hours every day, insufficient food intake could become a major problem.

Why WADA Is Urging Athletes to Be Cautious

Professor Rabin has advised athletes to be extremely careful about using these medications without proper medical supervision.

His concern is that GLP-1 drugs can cause substantial physiological changes.

Elite athletes are already pushing their bodies through unusually intense training and competition.

Adding a powerful medication without an appropriate clinical reason or medical oversight could create unnecessary risks.

The fact that a drug is not currently banned should therefore not be mistaken for evidence that it is automatically safe or appropriate for athletes.

Permitted does not mean risk-free.

Serena Williams Brought Athlete Use Into the Spotlight

One of the highest-profile sporting figures to publicly discuss using weight-loss medication is Serena Williams.

The 23-time Grand Slam singles champion revealed while away from professional tennis that she had used weight-loss medication after struggling to lose weight following childbirth.

Williams is also a spokesperson for Ro, a company that sells GLP-1 medications, and her husband is an investor in the business.

Her disclosure attracted additional attention to a subject that relatively few elite athletes have spoken openly about.

That lack of public discussion does not necessarily mean the drugs are absent from sport.

Emerging research suggests some athletes may already be using them.

Study Suggests Some Athletes Are Using GLP-1 Drugs Without Medical Need

A recent Loughborough University study surveyed more than 100 sports medicine physicians internationally.

According to the research, 12% said they were aware of athletes using GLP-1 medications despite not having a medical need for them.

That figure will be of obvious interest to WADA.

It suggests the issue is not purely theoretical.

If athletes are already experimenting with GLP-1 drugs for body-weight management rather than medical treatment, regulators need to understand both the scale of use and its consequences.

Aesthetic Sports Could Face Different Pressures

WADA is also considering sports where appearance can influence athlete behaviour.

Gymnastics is one example.

Horse riding has also been highlighted.

In some sporting environments, athletes may feel pressure to maintain a particular body shape even when there is no formal weight category.

That introduces a different concern.

The motivation for taking weight-loss medications may not always be performance in the strictest sense.

It could also involve appearance, selection pressures or sporting culture.

The Issue Could Extend Far Beyond Elite Competition

As GLP-1 medications become more visible in wider society, athletes are exposed to the same trends.

Social media discussions about rapid weight loss can further normalise their use.

Athletes may therefore encounter these medications not only through doctors but through teammates, friends, commercial promotions and online content.

That makes education increasingly important.

Why Weight Is Such a Sensitive Issue in Elite Sport

Many sports have complicated relationships with body weight.

Athletes are frequently encouraged to optimise body composition.

Sometimes that is genuinely linked to performance.

But excessive focus on weight can contribute to harmful behaviours.

Rapid weight cutting, extreme dieting and chronic under-fuelling can all affect health.

Introducing powerful weight-loss medications into that environment could create new risks.

That is why the conversation cannot be reduced to whether a drug appears on the banned list.

Athletes Still Need Enough Energy to Perform

Elite athletes require enormous amounts of energy.

Training places stress on muscles, bones, hormones and the cardiovascular system.

Recovery depends on sufficient nutrition.

If appetite suppression results in inadequate energy intake, athletes may struggle to recover properly.

Over time, that could affect performance as well as health.

The ideal sporting body is not simply the lightest possible body.

It is one capable of producing and sustaining the performance required.

Medical Use and Performance Use Are Not the Same Thing

Another important distinction concerns legitimate medical treatment.

GLP-1 drugs have established medical applications.

Athletes, like anyone else, may have health conditions for which these medications are clinically appropriate.

That is very different from a healthy athlete taking the medication solely to manipulate body weight.

Anti-doping regulators therefore face a difficult balance.

They need to identify potential abuse without unnecessarily restricting appropriate medical treatment.

Why WADA Has Not Rushed Into a Ban

It would be easy to assume that any substance capable of affecting weight should simply be prohibited.

But anti-doping decisions require evidence.

WADA needs to determine whether the drugs actually satisfy its criteria.

Do they improve performance?

How significant are the health risks for trained athletes?

How frequently are they being used without medical justification?

Could the disadvantages, such as muscle loss and fatigue, outweigh any possible sporting benefit?

Until those questions are answered more clearly, the drugs will remain under observation rather than prohibition.

Could Ozempic and Mounjaro Be Banned in 2028?

A future ban remains possible.

If WADA’s ongoing studies produce evidence supporting prohibition, the organisation could change its position.

Under its normal timetable, a decision approved at the executive committee meeting in September 2027 would generally take effect in January 2028.

That means 2027 could become a crucial year for determining the future status of GLP-1 medications in elite sport.

Being on WADA’s Monitoring List Still Matters

The monitoring programme exists to identify patterns before regulators decide whether stronger action is necessary.

Being monitored indicates that WADA considers the substance potentially relevant to doping.

Researchers can assess prevalence.

Scientists can evaluate physiological effects.

Sports authorities can monitor emerging trends.

And WADA can gather enough evidence to make a more informed decision later.

For GLP-1 drugs, this process appears far from over.

Athletes Should Not Treat the Decision as a Green Light

The most important message for athletes is that WADA’s 2027 decision is not an endorsement of recreational or performance-driven GLP-1 use.

The drugs remain legal under anti-doping rules.

But health considerations exist independently of anti-doping regulations.

Athletes considering such medication should therefore do so because of genuine clinical considerations and under appropriate healthcare supervision.

Using powerful medication purely because it is not currently prohibited carries obvious risks.

The Bigger Question: What Counts as Performance Enhancement?

The GLP-1 debate also illustrates how difficult modern anti-doping policy can become.

Traditional doping discussions often involve substances designed to increase:

• Strength
• Endurance
• Recovery
• Oxygen-carrying capacity

Weight-loss drugs present a different challenge.

Their potential benefit could be indirect.

They may not make an athlete stronger or faster pharmacologically.

Instead, they may alter body composition in a way that could theoretically improve performance in specific sports.

Determining whether that constitutes meaningful performance enhancement requires careful research.

The Bottom Line

Weight-loss medications such as Ozempic, Wegovy and Mounjaro will not be banned under WADA’s prohibited list for 2027.

But the decision should not be interpreted as the end of the debate.

Semaglutide has been monitored by WADA since 2024, while tirzepatide was subsequently added to the monitoring programme.

The agency is now conducting research to determine whether GLP-1 drugs could enhance sporting performance, pose sufficient health risks or be misused by athletes.

Sports involving strict weight management may attract particular attention, including boxing, wrestling and horse racing.

Cycling and long-distance running could also be relevant because body weight plays an important role in performance.

At the same time, possible side effects, including nausea, fatigue and muscle loss, mean using these drugs could actually undermine athletic performance.

WADA therefore wants more evidence before making a decision.

For now, the position is clear:

GLP-1 weight-loss drugs are permitted in elite sport in 2027, but they remain firmly on the anti-doping authority’s radar.

And depending on what the research reveals, the rules could look very different in 2028.

Source: BBC

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