People who rely on prescription weight loss injections may face a tough reality once the medication ends, as new research suggests most will steadily regain the weight they worked to lose.
A new analysis published by the British Medical Journal examined outcomes after patients stopped using weight management medications, including GLP-1 receptor agonists such as semaglutide and tirzepatide. These drugs are commonly sold under brand names like Ozempic, Wegovy, Mounjaro, and Zepbound.
According to the study, the goal was “to quantify and compare the rate of weight regain after cessation of weight management medications (WMMs) in adults with overweight or obesity.” The findings suggest weight regain begins quickly once treatment stops.
On average, participants regained about 0.4 kilograms, roughly 0.88 pounds, per month after discontinuing medication, according to a BMJ Group press release. At that rate, researchers projected that most people would return to their pre-treatment weight in under two years. The pace of weight regain was also significantly faster than what is typically seen after diet and lifestyle-based weight loss programs.
The study further found that people who used weight loss injections regained weight nearly four times faster than those who lost weight through dietary changes and physical activity once treatment ended. In addition to weight gain, markers linked to diabetes and heart disease were also predicted to return to baseline levels within the same timeframe.
Researchers from the University of Oxford reviewed data from 37 trials and observational studies published through February 2025, covering 9,341 participants. The average treatment period lasted 39 weeks, followed by about 32 weeks of monitoring after stopping medication.
Despite describing the injections as “highly effective” and acknowledging that they have “transformed the treatment of obesity,” researchers warned that medication alone may not support lasting weight control. As the study noted, “This evidence suggests that despite their success in achieving initial weight loss, these drugs alone may not be sufficient for long-term weight control.”
The authors also pointed out limitations in the data, including shorter follow-up periods for newer GLP-1 drugs. Even so, they said consistent results across multiple analyses strengthen confidence in the findings.
