Popular Weight Loss Drugs Work Fast—But the Weight Comes Back Even Faster

People who stop taking popular weight loss medications like Ozempic and Wegovy regain weight at nearly four times the rate of those who lose weight through diet and exercise alone. A comprehensive analysis published in The BMJ found that the impressive weight loss achieved with glucagon-like peptide-1 (GLP-1) drugs often disappears within two years of stopping treatment, along with most heart and metabolic health benefits.

How Fast Do People Regain Weight After Stopping GLP-1 Drugs?

Researchers from the University of Oxford analyzed 37 studies involving 9,341 participants who used weight loss medications including semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound). They found people regained an average of 0.4 kilograms per month (approximately 0.88 pounds) after discontinuing these drugs. At this rate, body weight returns to pre-treatment levels within approximately 1.7 years.

The speed of weight regain was consistently faster following drug-based weight loss compared to behavioral weight management programs, with an average difference of 0.3 kilograms per month (approximately 0.66 pounds). This pattern held true regardless of how much weight participants initially lost during treatment.

What Health Benefits Disappear When Treatment Stops?

The study revealed that stopping GLP-1 medications doesn't just affect weight—it also reverses many health improvements. Cardiometabolic risk markers, including measures related to heart disease and diabetes, were projected to return to baseline levels within roughly 1.4 years after medication discontinuation.

Key health benefits that fade after stopping treatment include:

• Cholesterol improvements: Lower cholesterol levels achieved during treatment gradually return to pre-medication levels
• Blood pressure reductions: Improvements in blood pressure control tend to reverse within the follow-up period
• Diabetes risk markers: Metabolic health gains related to blood sugar control diminish over time

"This evidence suggests that despite their success in achieving initial weight loss, these drugs alone may not be sufficient for long term weight control," the researchers write.

Why Do So Many People Stop Taking These Medications?

Despite their effectiveness, about half of people with obesity discontinue GLP-1 drugs within a year of starting treatment. This high discontinuation rate makes understanding post-treatment outcomes especially important for patients and healthcare providers.

The research team followed participants for an average of 32 weeks after they stopped taking weight loss medications. While only eight studies specifically examined newer GLP-1 medications, and none followed participants for more than 12 months after stopping treatment, the researchers used three different analytical approaches that all produced similar results.

Meanwhile, separate research from the University of North Carolina Nutrition Research Institute suggests that biology, not willpower, may determine weight loss success. Scientists found that small molecules called metabolites in urine samples could predict which individuals would respond best to calorie-restricted diets before they even began dieting.

"What surprised us most was that we could see a clear landscape of different metabolites before any weight loss occurred," said Evan Paules, the study's lead author. "Those early signals helped distinguish which mice would later respond well to calorie restriction."

A US researcher emphasized in a linked editorial that "people taking GLP-1 receptor agonists should be aware of the high discontinuation rate and the consequences of cessation of medications." He added that "healthy dietary and lifestyle practices should remain the foundation for obesity treatment and management, with medications such as GLP-1 receptor agonists used as adjuncts."

The findings suggest that successful long-term weight management may require ongoing treatment or comprehensive lifestyle changes that extend beyond medication alone. As researchers continue investigating cost-effective strategies for sustained weight control, the emphasis remains on combining medical interventions with lasting behavioral modifications.