People who stop using weight-loss injections regain all the weight they lost in under two years, according to a major new analysis. The study, led by researchers at the University of Oxford and published in the BMJ, reviewed 37 studies involving more than 9,300 participants using GLP-1 agonist medications. These drugs, originally developed for diabetes, suppress appetite by mimicking the GLP-1 hormone.
Researchers found that after stopping treatment, participants regained weight at an average rate of 0.4kg per month, returning to their original weight within about 1.7 years. On average, people lost 8.3kg while on medication but regained 4.8kg within the first year after stopping. Weight returned almost four times faster than after behavioural weight-loss programmes such as diet and exercise plans.
Dr Sam West from Oxford said the findings reflect obesity’s chronic, relapsing nature rather than a failure of the drugs themselves. The study also found that improvements in blood pressure and cholesterol reversed within roughly 1.4 years of stopping treatment.
Experts from Diabetes UK and the Obesity Health Alliance stressed that weight-loss drugs are effective tools but not a quick fix. They emphasised the need for long-term lifestyle support and healthier food environments to sustain benefits once medication ends.
