New Study Shows Weight Starts Returning Within Weeks After Stopping Obesity Drugs

New evaluation of worldwide clinical trials shows that weight lost on anti-obesity drugs returns in weeks after treatment stops. Indeed, subjects started to regain weight in Week 8, and this rebounding persisted until Week 20. Some regained a large percentage of the lost kilos within a few months.

The rebound effect was particularly significant with GLP-1 receptor agonists—a class that encompasses commonly prescribed medications such as semaglutide and tirzepatide.

Interestingly, more initial weight loss at the time of treatment and continued lifestyle interventions were associated with even more intense rebound patterns.

This trend isn't merely a clinical aside—it's a real-world issue. Example: patients who received 36 weeks of tirzepatide regained almost as much as half the weight lost after stopping.

Experts caution the implications are not just the size. Weight gain can also undo gains in metabolism, blood pressure, lipids, and glucose control.

And whereas weight rebound is recognized in other therapies—such as bariatric surgery and lifestyle modification—this meta-analysis provides a quantitative and systematic image for anti-obesity medications.

Interested in finding out why weight keeps coming back after treatment is stopped—and what it implies about managing obesity in the long run? Click here to find out.