Expert Witness Journal Issue 66 April 2026 - Flipbook - Page 37
Weight loss drugs in sport — WADA’s
watchlist, performance trade o昀昀s &
what athletes need to know
by Georgina Rothwell, Thorrun Govind, Catherine Forshaw at Brabners.
GLP-1 drugs like Ozempic and Mounjaro have
recently made waves in sport with elite athletes —
including former tennis player Serena Williams —
bringing attention to their use. Originally developed
for diabetes and weight management, these
medications are now part of a broader conversation
about performance, recovery and regulation.
Why athletes are considering GLP-1s
Health improvements
When used for their intended medical purposes,
GLP-1 drugs can deliver substantial health bene昀椀ts.
Athletes who meet clinical criteria may see better
glycaemic control, improved cholesterol and
triglycerides and lower rates of major adverse
cardiovascular events. For master athletes or those
with metabolic issues, that can be life-changing in
the long run.
While GLP-1s haven’t been banned by the World
Anti-Doping Agency (WADA), they’re being actively
monitored. This is a formal step used to track
substances that might enhance performance, pose
health risks or undermine the spirit of sport. That
status matters because labs are already looking
for patterns of use and — if evidence of abuse
emerges — GLP-1 drugs could shift from ‘watched’
to ‘prohibited’ in a future ‘Prohibited List’ update.
However, these bene昀椀ts are documented in
therapeutic contexts with medical oversight.
Translating them directly into safe performance
gains isn’t automatic.
Competitive advantages
The most compelling sport-speci昀椀c draw is
improved relative power. If your ‘engine’ stays the
same while the ‘chassis’ gets lighter, climbing and
long-course economy can improve. That’s why some
swimmers, cyclists and triathletes are discussing the
use of GLP-1s and why WADA’s science leadership
has publicly 昀氀agged possible advantages based on
weight-to-power dynamics.
Here, Georgina Rothwell, Thorrun Govind and
Catherine Forshaw explore what’s known, what’s
emerging and what athletes need to consider as
interest grows and scrutiny intensi昀椀es.
Why sport is watching Ozempic
Ozempic is the brand name for semaglutide — a
GLP-1 receptor agonist originally designed for type
2 diabetes. At higher doses, it was later approved
for chronic weight management. In simple terms,
semaglutide helps the pancreas to release insulin
when needed, suppresses glucagon, slows gastric
emptying and reduces appetite. These e昀昀ects
improve metabolic control and make it far easier to
maintain a calorie de昀椀cit.
It’s important to note that these advantages aren’t
universal. Sprint power, repeated accelerations and
collision resilience depend heavily on lean mass.
If your weight loss includes muscle (and for many
athletes, it does), the net e昀昀ect can be neutral — or
even negative.
Side e昀昀ects that shape performance
This is why endurance and weight-sensitive sports
are paying attention. Less body mass can mean
a better power-to-weight ratio without living in a
constant state of hunger that typically comes with
cutting weight. It’s a clear performance incentive
which is precisely why WADA placed GLP-1s on its
‘Monitoring Program’.
EXPERT WITNESS JOURNAL
Athletes often experience two very di昀昀erent realities
on GLP-1s. On one hand, appetite suppression and
steadier blood sugar can make it easier to stay in a
small, consistent energy de昀椀cit without the mood
swings and constant cravings that sabotage dieting.
On the other hand, a meaningful portion of weight
loss can be lean tissue — especially when protein
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APRIL 2026
