Published Mar 12, 2026 | 7:00 AM ⚊ Updated Mar 12, 2026 | 7:00 AM
Drugs such as Ozempic and Wegovy act like brakes on our appetite, making us feel full sooner,
Synopsis: Researchers tracked 3,236 patients who had discontinued GLP-1 drugs. Weight regain followed a predictable pattern, but raised muscle-loss concerns.
People regain an average of 60% of their lost weight within a year of stopping weight-loss drugs like Ozempic and Wegovy, according to a study by a group of researchers at the University of Cambridge.
The work, published in eClinicalMedicine, analysed 48 studies comprising 3,236 participants who had discontinued GLP-1 receptor agonists including semaglutide, tirzepatide and liraglutide.
Researchers tracked weight changes for up to 52 weeks after patients had stopped medication.
Weight regain followed a consistent mathematical pattern across all drugs studied. Patients experienced rapid initial regain that progressively slowed. By one year, they had regained 60% of their lost weight. Beyond 52 weeks, the researchers’ model predicted weight regain would plateau at 75% of the original weight loss, meaning 25% of the initial reduction would persist long-term.
“At one year post-cessation, 60% of the weight lost during treatment was regained. Beyond 52 weeks, weight trajectories were extrapolated, with weight regain estimated to plateau at 75.3% of the weight lost on treatment,” the study noted.
For someone who had lost 20 kilograms on undergoing treatment, it meant regaining approximately 12 kilograms within the first year, then another three kilograms over subsequent months, settling at five kilograms below their starting weight. The half-life of weight regain measured 23 weeks, meaning half of all the weight that would eventually return had already returned by then.
“Drugs such as Ozempic and Wegovy act like brakes on our appetite, making us feel full sooner, which means we eat less and therefore lose weight,” explained Brajan Budini, a medical student at the School of Clinical Medicine and Trinity College, University of Cambridge. “When people stop taking them, they are essentially taking their foot off the brake, and this can lead to rapid weight regain.”
The model estimated a recovery rate constant of 0.0302 per week, corresponding to the 23-week half-life. Weight regain trajectories appeared broadly similar across trials of liraglutide, semaglutide and tirzepatide, suggesting the pattern held regardless of the GLP-1 drug used.
The study highlighted a critical gap in current research: during treatment, 40 to 60% of the weight lost comprised muscle rather than fat. After stopping medication, researchers could not determine whether people regained muscle and fat proportionally or whether the regained weight arrived predominantly as fat.
“There are significant concerns about the long-term consequences of GLP-1R drugs on body composition, with studies indicating that 40 to 60% of the weight lost during treatment is muscle,” the study noted.
“Our projections show that even though people regain most of the weight they have lost, they still maintain some of the weight loss, but what we currently don’t know is if the same proportion of lean mass is recovered,” Budini said.
“If the regained weight is disproportionately fat, individuals may ultimately be worse off than before in their fat-to-lean mass ratio, which may have adverse consequences for their health,” the researcher further stated.
A person who lost 20 kilograms might have lost eight to 12 kilograms of muscle during treatment. If the 12 kilograms regained were fat, then they would weigh less, but carry more fat and significantly less muscle than in the pre-treatment period. Less muscle meant slower metabolism, reduced strength, higher risk of falls and fractures, and worse metabolic health despite lower total weight.
Studies have not measured body composition changes during the weight regain phase, leaving this critical question unanswered.
Approximately half of patients who start GLP-1 drugs discontinued within the first year, with three-quarters stopping after two years. The study attributed this to “their potential side effects and to limited access under insurance coverage policies and national prescribing guidelines.”
Reasons for discontinuation include gastrointestinal side effects such as nausea, vomiting and diarrhoea, financial constraints, and limited insurance coverage.
In the UK, the National Institute for Health and Care Excellence had recommended semaglutide for weight loss for a maximum of two years but set no limit for tirzepatide, creating what the researchers called an “inconsistency” that “highlights a blind spot in long-term obesity management.”
Beyond weight, the study examined changes in blood sugar control and blood pressure after patients stopped taking GLP-1 drugs.
HbA1c, a measure of average blood sugar, typically dropped 0.5 to 1.5 percentage points during treatment. After stopping, about half of this reduction disappeared within eight to 12 weeks. However, levels rarely returned fully to baseline even after one year.
Systolic blood pressure fell by one to 10 millimetres of mercury during treatment. After stopping, 70 to 80% of this reduction reversed within 12 weeks.
Researchers noted that GLP-1 drugs might help patients develop healthier eating habits during treatment—such as reduced portion sizes or improved nutritional quality—that persist after discontinuation. The drugs could also facilitate long-term physiological adaptations, altering hormone levels or resetting hypothalamic appetite control mechanisms.
“When stopping weight loss drugs, doctors and patients should be aware of the potential weight regain and consider ways to mitigate this risk,” said Steven Luo, a medical student at the School of Clinical Medicine and Trinity College.
“It’s important that people are given advice on improving their diet and exercise, rather than relying solely on the drugs, as this may help them maintain good habits when they stop taking them,” he said.
The researchers acknowledged several important limitations. Most critically, the trial data used to fit their model only extended to 52 weeks after cessation.
“No large-scale trials have reported weight regain data beyond this point; thus, predictions made outside of this window are extrapolations,” they wrote.
The analysis restricted inclusion to studies where participants lost at least three kilograms during treatment. The researchers acknowledged that “patients achieving more modest weight loss are a clinically important subgroup and their post-cessation weight trajectories may not mirror those presented in our analysis.”
The study could not determine whether concomitant medications, weight maintenance strategies, or different health conditions affected regain patterns because “data were typically not reported in sufficient detail, often only with broad summary statistics or not at all.”
Most studies included in the review were not designed to measure post-cessation outcomes as a primary endpoint.
“Most trials were not explicitly designed to measure post-cessation outcomes and only extended data collection beyond treatment cessation for exploratory or safety reasons,” the researchers noted. Risk of bias assessments found most studies had a moderate risk, “primarily due to the absence of pre-specified post-cessation outcomes in study protocols or analysis plans.”
Looking forward, newer and more potent drugs have been entering clinical development. Retatrutide, currently in clinical trials, targets three hormone receptors—GLP-1, GIP and glucagon—and has produced 24% weight loss after 48 weeks of treatment in early results.
If regain patterns remained consistent, more potent drugs producing greater initial weight loss might leave larger residual benefits even after stopping. However, the researchers cautioned that faster and larger weight loss typically accelerated muscle depletion alongside fat loss.
The researchers called for additional research. “We recommend that future trials investigate further the effect of GLP-1RAs on the composition of weight loss during and after treatment cessation and how these changes compare to other weight loss modalities,” they wrote.
The study concluded that “GLP-1RA cessation is associated with a predictable and decelerating pattern of weight regain, which appears to plateau below pre-treatment levels, suggesting that partial weight-loss benefit may persist long-term but is substantially attenuated.”
The study was conducted by a team of students at Trinity College, University of Cambridge, and published in eClinicalMedicine. The research followed Cochrane and PRISMA guidelines for systematic reviews and meta-analyses.
(Edited by Majnu Babu).
