BMJ meta-analysis quantifies weight regain after stopping obesity drugs

People who stop taking a weight-management medication regain weight at an average of about 0.4 kg (roughly 0.9 pounds) per month, and the improvements those drugs produce in blood pressure, cholesterol and blood sugar markers are projected to return to pre-treatment levels within about 1.4 years, according to a systematic review and meta-analysis published by The BMJ ^[1].

The researchers searched Medline, Embase, PsycINFO, CINAHL, Cochrane, Web of Science and trial registries from inception through February 2025, screening 9,288 titles ^[1]. They included randomized controlled trials, non-randomized trials and observational studies in adults with overweight or obesity that used a weight-management medication for at least eight weeks and followed participants for at least four weeks after treatment stopped ^[1]. Thirty-seven studies met the bar, covering 63 intervention arms and 9,341 participants ^[1]. Average treatment lasted 39 weeks, with a range of 11 to 176 weeks, and average follow-up after stopping was 32 weeks, ranging from 4 to 104 weeks ^[1].

What the numbers show

The headline figure was an average monthly weight regain of 0.4 kg (95% confidence interval 0.3 to 0.5) after medication stopped ^[1]. When the analysis was restricted to randomized trials and compared with control groups, the mixed model estimated 0.3 kg (0.2 to 0.4) of regain per month relative to control ^[1]. That gap between the two figures reflects the fact that control groups also tend to drift over time.

All cardiometabolic markers tracked in the review were projected to return to baseline within 1.4 years of stopping the drug ^[1].

The review also compared drugs with behavioral weight management programs. Regain was faster after medication than after a behavioral program, by 0.3 kg (0.22 to 0.34) per month, and that difference held regardless of how much weight a person had lost in the first place ^[1]. In other words, the faster rebound was not simply explained by drugs producing larger losses. The authors reported that their estimates and their precision held up in sensitivity analyses ^[1].

One important limit sits in the study's own figures: follow-up data were not available beyond 52 weeks for the newer and more effective incretin mimetics, semaglutide and tirzepatide ^[1]. For those medications specifically, the line showing weight returning all the way to baseline is a model projection extended past the observed data, not a measurement ^[1]. The abstract does not break out separate monthly regain rates for semaglutide or tirzepatide alone, so how closely those drugs match the 0.4 kg average is not yet clear from this publication.

The authors' conclusion is blunt: stopping a weight-management medication is followed by rapid weight regain and reversal of the benefits to cardiometabolic markers, and the findings "suggest caution in short term use of these drugs without a more comprehensive approach to weight management" ^[1].

Why it matters for patients

Many US patients do not stay on GLP-1 medications for years. Coverage lapses, cost, supply issues and side effects all end treatment. This analysis puts a number on what tends to happen next, and it is a slow but steady climb rather than an immediate snap back: about 0.4 kg per month on average, which works out to roughly 5 kg (about 11 pounds) over a year at that pace ^[1].

The cardiometabolic finding may matter as much as the scale. Improvements in markers like blood pressure and lipids were projected to disappear within about 1.4 years of stopping ^[1]. That reframes these medications as ongoing treatment for a chronic condition rather than a short course.

The comparison with behavioral programs is also notable. Losing weight through a behavioral program was followed by slower regain than losing the same amount on medication ^[1]. The review does not explain the mechanism behind that difference, and the abstract does not report how many participants in either group continued any support after treatment ended.

A few caveats are worth keeping in view. This is a pooled analysis of studies with widely varying treatment lengths and follow-up windows, and it covers all weight-management medications, not just GLP-1 drugs ^[1]. Averages describe groups, not individuals. The review was registered in advance (PROSPERO CRD42024532069) and used standard risk-of-bias tools, the Cochrane Risk of Bias 2 tool for randomized trials and ROBINS-I for non-randomized ones ^[1].

Funding came in part from the National Institute for Health and Care Research Oxford Biomedical Research Centre ^[1]. Several authors disclosed publicly funded trials with weight-loss products donated by Nestlé Health Science, Oviva or Second Nature, and one author receives, with two others partially funded by, a research grant from the Novo Nordisk Foundation ^[1].