Weight Loss Injections Can Lead to Substantial Regain After Stopping Treatment

New study finds patients may regain two-thirds of lost weight within a year of discontinuing GLP-1 medications like Mounjaro and Wegovy

Published on Mar. 5, 2026

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A new study by researchers at Cambridge University analyzed data from over 3,200 people using weight loss injection medications like Mounjaro and Wegovy. The findings show that individuals can regain approximately 60% of their lost weight within a year of stopping treatment, highlighting the substantial rebound effect that can occur. While the rate of weight regain slows over time, experts emphasize the need for ongoing lifestyle changes and strategies to minimize weight regain when discontinuing these medications.

Why it matters

The study underscores the challenges of long-term weight management, as many patients struggle to maintain weight loss achieved through medication alone. It raises important questions about the sustainability of these treatments and the need for a more comprehensive approach to obesity treatment that integrates medication with lifestyle interventions.

The details

The study found that while patients were able to maintain around 25% of their initial weight loss in the long term, a significant portion - around half - of the weight lost during treatment was muscle mass. This shift in body composition can have negative health consequences if the weight regained is primarily fat. Experts recommend a focus on strength training during and after medication use to help preserve muscle mass and improve metabolic health.

  • The study analyzed data from six clinical trials involving over 3,200 people using GLP-1 medications.
  • Participants regained an average of 60% of their lost weight 52 weeks after stopping medication.
  • The rate of weight regain slows after approximately 60 weeks off medication, with patients typically regaining around 75% of their initial weight loss.

The players

Cambridge University

The institution where the researchers who conducted the study are based.

Brajan Budini

One of the study's authors, who explained that the suppression of appetite caused by these medications can lead to rapid weight gain when people stop taking them.

Steven Luo

Another author of the study, who stressed the importance of preparing both doctors and patients for the risk of weight regain when discontinuing weight loss medications.

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What they’re saying

“When people stop taking these drugs, the suppression of appetite is removed, which can lead to rapid weight gain.”

— Brajan Budini, Study Author

“The findings highlight the substantial weight regain that can occur after discontinuing GLP-1 drugs.”

— Steven Luo, Study Author

What’s next

Researchers emphasize the need for further investigation into how weight regain impacts the fat-to-muscle ratio, as well as the development of strategies for gradual medication tapering and ongoing lifestyle support to minimize weight regain.

The takeaway

The study underscores the importance of a comprehensive approach to weight management that goes beyond just achieving weight loss through medication. Integrating GLP-1 agonists with behavioral therapy, nutritional counseling, and exercise programs may be key to helping patients maintain their weight loss in the long term.