Post-Treatment Weight Rebound in Patients Using Anti-Obesity Medications

Recent research indicates that individuals prescribed anti-obesity medications may experience significant weight regain after discontinuing their treatment. A comprehensive meta-analysis, published in BMC Medicine, analyzed data from 11 international studies involving 1,574 participants on medication and 893 control subjects. The findings reveal that while these medications effectively promote weight loss during use, the effects diminish—often sharply—within weeks after cessation.

The study categorized the medications into several types, including GLP-1 receptor agonists (such as semaglutide), dual GLP-1 and dual receptor agonists, orlistat, phentermine-topiramate, and naltrexone-bupropion. The analysis controlled for various factors such as the presence of diabetes and lifestyle changes like diet and exercise.

Results showed that weight loss peaks during treatment but begins to reverse approximately eight weeks after stopping medication. Weight regain continues over an average of 20 weeks before reaching a plateau. The extent of weight regain varies depending on several factors, including the specific medication used and adherence to lifestyle modifications. For instance, individuals who completed a 36-week tirzepatide regimen regained nearly half of the weight lost after switching to a placebo.

The researchers highlight that these findings do not compare medication effects with lifestyle interventions or surgical options like bariatric surgery. Nonetheless, the evidence underscores the challenge of maintaining weight loss after pharmacological treatment ends. The study emphasizes ongoing weight management strategies and regulatory considerations for long-term treatment plans.

In conclusion, anti-obesity drugs are effective for short-term weight reduction, but many patients tend to experience weight rebound after stopping treatment. This underscores the importance of continued support and the potential need for adjunct therapies or lifestyle modifications to sustain weight loss over time.

Source: https://medicalxpress.com/news/2025-07-anti-obesity-medications-weight-rebound.html