Will You Gain Weight After Stopping a GLP-1? New Study Says 'Yes'

A new study was published in BMC Medicine on July 22, 2025 entitled "Trajectory of the body weight after drug discontinuation in the treatment of anti-obesity medications."

The study wants to answer a question many people want to know: Will you gain weight after stopping GLP-1 medications like semaglutide. Researchers estimate that 3.3 billion adults will deal with obesity by 2030--up from the 2.2 billion we've seen globally, as of 2020.

The study aimed to see how well anti-obesity medications (AOMs) continued to work after discontinuation. Did people stay the same weight after stopping and AOM like a GLP-1, did they lose weight, or even gain the weight back?

After four weeks, those in the AOM group still had weight loss (when compared with those taking no weight loss meds). After eight weeks, the weight started coming back, as the weighted mean difference (WMD) rose to plus 3.33 pounds at that time. At 12 to 20 weeks, the WMD rose to 3.9 pounds.

Among the different subgroups of AOMs, significant weight regain after 12 weeks of drug discontinuation was observed only in studies with glucagon-like peptide 1 receptor agonist (GLP-1 RA) related drugs. In addition, studies in which weight loss was greater during treatment than in the control group and studies in which lifestyle interventions were continued observed significant weight gain after drug discontinuation, according to the results.

Weight regains seemed to level off at around six months for participants, showing that the most significant regaining might happen in the first six months after discontinuing treatment. The researchers report no correlation between the rate at which a person loses weight on a GLP-1 med, and the rate at which they regain weight upon discontinuing those medications.

Although the review found that weight gain is likely after discontinuing weight loss meds like GLP-1s, the researchers acknowledge limitations on the data, such as small sample sizes and not including information on bariatric surgery history (if applicable) and lifestyle info among participants.