Stopping GLP-1 Jabs Triggers Rapid Weight Gain

Stopping popular weight-loss shots brings a risk of rapid weight gain, according to new research. A review of 37 clinical trials and observational studies involving more than 6,000 overweight or obese individuals on GLP-1 drugs like Wegovy and Mounjaro and 3,000 others in behavioral weight management programs found those who came off the drugs regained just shy of a pound per month on average, per the CBC. That would put many back at their starting weight in roughly 18 months, compared to four years for those who had lost weight through diet or other behavioral changes. Those individuals tended to regain just 0.2 pounds a month, though researchers note more long-term, real-world data is needed.

The rapid weight gain after coming off GLP-1s was "particularly shocking," Oxford University's Sam West, lead author of the study published Wednesday in the British Medical Journal, tells the CBC. The drugs mimic a hormone, GLP-1, that helps control appetite. Nutrition scientist Dr. Adam Collins of the University of Surrey says long-term use may dial down the body's own GLP-1 production and sensitivity, so when injections stop, hunger rebounds sharply and overeating becomes more likely, per the BBC. Some users describe it as feeling "instantly starving," with one woman saying it was like a mental switch flipping to: "Eat everything." Collins warns the challenge is greater if patients relied on the injections alone without building lasting diet and behavior changes.

A large Danish study published last year found more than half of adults without diabetes stopped using GLP-1s within a year, in part due to cost and gastrointestinal side-effects, as the CBC reports. The average length of treatment in the meta-analysis was 39 weeks. Some specialists argue treatment should often be long-term, likening obesity to other chronic conditions. Pharmaceutical makers Eli Lilly and Novo Nordisk echo that view, saying weight often comes back when therapy stops, not because of a lack of effort, but because of how the disease works. In other words, GLP-1s should not be considered a quick fix.