What happens to weight when people stop taking GLP-1 drugs?

On average, a lot of the weight comes back. A 2025 systematic review found that after stopping semaglutide, people regain on average 67% of the weight they lost within the following year, and return to their previous weight within a year and a half on average. For tirzepatide, a summary says patients regain more than half the weight they lost within a year, often returning to their previous weight within a year and a half. These are averages across groups, not forecasts for any one person, and this lesson only describes the evidence.

The clearest single example is an extension of STEP 1, a trial funded by the drug's maker. People had lost 17.3% of their weight on semaglutide by week 68; after stopping, they regained 11.6 percentage points by week 120, leaving a net loss of 5.6%. The authors summed it up as regaining two-thirds of their prior weight loss in a year, the same figure a Novo official cited in March 2023.

Regain is an old story, not a new one. Weight cycling, or yo-yo dieting, is the repeated loss and gain of weight. It is often set off by strict diets that cannot be kept up, when the dieter gives up because of hunger or discomfort and gains the weight back. A source on obesity says many people attempt to lose weight and are often successful, but maintaining the loss long-term is rare, and it puts success rates of long-term maintenance with lifestyle changes at 2 to 20%.

Why do people stop? In the United States, cost is the highest barrier to GLP-1 use, and it was reported as the reason by 48.6% of people who stopped. The weekly injection is another reason for discontinuation, according to one source.