People Who Stop Taking Weight-Loss Jabs Regain Weight Within 2 Years, Study Says

Those taking weight-loss drugs are likely to regain the weight they have lost within two years of stopping the medication, a new study has found.

Research published by the British Medical Journal (BMJ) looked into what happens when those taking “weight management medications such as glucagon-like peptide-1 (GLP-1) receptor agonists including semaglutide and tirzepatide” stop treatment, per a BMJ Group press release.

Semaglutide is sold under brand names Ozempic and Wegovy, while tirzepatide is sold under brand names Mounjaro and Zepbound.

The study’s objectives were “to quantify and compare the rate of weight regain after cessation of weight management medications (WMMs) in adults with overweight or obesity,” per an abstract of the study.

The press release for the study says that on average people using weight-loss drugs regain 0.4kg (approximately 0.88 lbs.) a month after stopping the medication and all weight lost is likely to be regained in under two years. Weight regain is also faster after stopping the medication than after “dietary weight loss programmes.”

According to the study, those taking weight-loss injections could regain weight almost four times faster than they would after dieting once they stop taking the medication.

Despite acknowledging that the “highly effective” injections had “transformed the treatment of obesity,” the BMJ Group’s release noted that “it is estimated that around half of people with obesity discontinue GLP-1 drugs within 12 months, so it’s important to understand what happens to body weight and risk markers for conditions like diabetes and heart disease after stopping treatment.”

The release stated, “To do this, a team of researchers from the University of Oxford searched registries and databases for trials and observational studies that compared the effects of any medication licensed for weight loss in adults with any non-drug weight loss intervention (behavioural weight management programmes) or placebo.”

Researchers looked at 37 studies published up to February 2025 involving 9,341 participants, per the data, which pointed out that the average duration of weight loss treatment was 39 weeks, with an average follow-up of 32 weeks.

The data suggested that after stopping the medication, “Participants treated with weight loss drugs regained on average 0.4 kg/month,” which is equivalent to nearly 0.9 lbs per month, according to the release.

The study also showed that “weight and risk markers for diabetes and heart disease [were] predicted to return to pre-treatment levels in less than two years,” after stopping treatment, the release added.

The findings also suggested “that the rate of weight regain after stopping weight loss drugs” was “almost four times faster than after diet and physical activity changes, irrespective of the amount of weight lost during treatment.”

“This evidence suggests that despite their success in achieving initial weight loss, these drugs alone may not be sufficient for long term weight control,” researchers noted, per the release.

The study’s results added that “all cardiometabolic markers were projected to return to baseline within 1.4 years after the cessation” of weight management medications.

Investigator Dr. Susan Jebb, from Oxford University, said, “People buying these need to be aware of the risk of fast weight regain when the treatment ends,” but pointed out that the study’s findings came from medical trials rather than real life, per the BBC. She said further studies into the longer-term effects of the medications would be helpful.

The BMJ study’s authors acknowledged several limitations with the data, per the BMJ Group’s press release.

“For example, only eight studies assessed treatment with the newer GLP-1 drugs and the maximum follow-up period in these studies was 12 months after medication stopped. What’s more, few studies were at low risk of bias,” the release noted.

“Nevertheless, they point out that they used three methods of analysis and all provided similar results, adding certainty to their findings,” it added.

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Dr. Adams Collins, a nutrition expert at the U.K.’s University of Surrey, says the injections mimic a natural hormone called GLP-1, which regulates hunger, per the BBC.

“Artificially providing GLP-1 levels several times higher than normal over a long period may cause you to produce less of your own natural GLP-1, and may also make you less sensitive to its effects,” he said, according to the outlet.

“That’s not a problem when taking the drugs, but as soon as you withdraw this GLP-1 ‘fix,’ appetite is no longer kept in check and overeating is far more likely,” Collins told the BBC.

PEOPLE reached out to one of the BMJ study’s researchers, Sam West, for comment, but didn’t immediately hear back.