Anti-obesity drugs: medical revolution or slimming mirage?

Tennis champion Serena Williams is lending her image to a new generation of treatments that are revolutionizing obesity management: GLP-1 analogues. Initially designed for diabetes, these drugs, such as Ozempic (semaglutide), Wegovy , and Mounjaro (tirzepatide), are now being prescribed for weight loss, with spectacular results. But behind the hype, experts are urging caution.

GLP-1 is a hormone naturally produced by the body after a meal. It stimulates insulin, slows gastric emptying, and acts on the brain to induce satiety.

In the drug version, injected once a week, this hormone acts as an appetite suppressant and regulates blood sugar. Weight loss rates have been observed to reach 15 to 20% of body weight, an unprecedented figure compared to other available treatments.

Dr. Aurel Guedj points out that while these treatments are effective, they are not without their limitations. The positives:

• Significant and lasting weight loss as long as treatment is continued.
• Reduction of cardiovascular risk in fragile patients.
• Change of perspective: obesity is finally recognized as a complex chronic disease , and no longer as a simple lack of willpower.

The gray areas:

• Common digestive side effects: nausea, vomiting, diarrhea.
• One in two patients abandons treatment in real life.
• When stopped, weight rebounds : two-thirds of the weight lost is regained within a year.
• Worrying muscle loss: In one study, for every 10 kilos of fat lost, nearly 7 kilos of muscle also disappear , which weakens metabolism and accelerates aging.

• Europe (EMA) : Wegovy authorized since 2022, Mounjaro since 2024. Indications: BMI ≥30, or ≥27 with comorbidity (hypertension, diabetes, sleep apnea, cholesterol).
• France : Reimbursement only for cases of severe obesity (BMI ≥35), under specialist monitoring. Objective: to avoid massive prescriptions outside of a medical setting.

But in practice, a parallel market is emerging: "off-reimbursement" prescriptions for patients who are simply overweight and are prepared to pay for the treatment themselves.

The global market for these drugs could reach $100 billion by 2030. In France, some fear a two-tier system:

• several hundred thousand patients medically monitored and reimbursed,
• millions more accessing injections through liberal prescription, without supervision.

The risk: reducing obesity to a simple injection, to the detriment of prevention, balanced diet, and physical activity. These drugs represent a major step forward in the fight against obesity. But they must remain medically regulated.

Behind the image of a miracle solution lies a more complex reality: muscle loss, treatment dependence, and rebound upon cessation. The real challenge remains the same: treating obesity as a chronic disease, but without forgetting the essential pillars of nutrition, physical activity, and prevention.