Stopping Ozempic or Mounjaro? The weight may come back faster than you think

New research shows people regain weight far faster after stopping obesity drugs than after dieting, with benefits fading quickly and raising questions about how long GLP-1 medicines need to be taken

You lose weight on an obesity drug, but what happens when you stop taking it? A new study suggests the weight often comes back faster than many people expect.

 

Research titled Weight regain after cessation of medication for weight management, published in the journal The BMJ, shows that most people regain weight rapidly after stopping weight-loss drugs, such as GLP-1 receptor agonists, returning to their original weight in less than two years.

 

The analysis, based on data from over 9,000 participants, also finds that weight regain after stopping these medications is much faster than after diet and exercise programmes, raising concerns about how sustainable drug-led weight loss really is.

 

What did the BMJ study examine about stopping obesity drugs?

The researchers wanted to understand how quickly people regain weight after stopping weight-management medications, and how this compares with weight regain after behavioural approaches such as diet and physical activity. They also looked at what happens to health markers such as blood sugar, cholesterol and blood pressure once the drugs are stopped.

 

To do this, they conducted a systematic review and meta-analysis of 37 studies published up to February 2025, covering 9,341 adults with overweight or obesity.

How fast does weight return after stopping Ozempic, Mounjaro and similar drugs?

On average, people regained about 0.4 kg every month after stopping weight-loss medication. At this pace, most returned to their baseline weight in around 1.7 years.

 

For newer, more potent drugs such as semaglutide (including Ozempic, Wegovy and Rybelsus) and tirzepatide (including Mounjaro and Zepbound), the rebound was even faster, with weight projected to return to baseline in about 1.5 years.

 

The study also found that people coming off diet-and-exercise programmes regained weight much more slowly and, on average, took almost four years to return to baseline weight.

What happens to blood sugar and heart health after stopping GLP-1 drugs?

The benefits do not just fade on the weighing scale. Improvements in key cardiometabolic markers, including blood sugar (HbA1c), fasting glucose, cholesterol, triglycerides and blood pressure, also reversed after stopping medication.

 

The study projects that most of these health gains return to baseline within about 1.4 years of stopping treatment, mirroring the pattern seen with weight regain. 

Why does weight rebound so quickly after stopping obesity injections?

Obesity drugs work largely by suppressing appetite and increasing feelings of fullness. Once the drug is withdrawn, hunger signals often return, making it harder to sustain the same eating patterns.

 

Unlike behavioural programmes, which may leave people with long-term coping strategies around food and activity, medications can make behaviour change feel effortless until they are stopped.

Do these findings mean Ozempic and Mounjaro don’t work?

According to the study, the drugs are highly effective at producing significant weight loss and improving metabolic health while they are being taken. The research does not question their short-term benefits.

 

What it does highlight is that short-term use alone is unlikely to lead to lasting weight control for most people.

Why do so many people stop taking GLP-1 weight-loss drugs?

Real-world data suggest that around half of people discontinue obesity medications within a year, often due to cost, side effects, access issues or expectations around long-term use.

Are obesity drugs meant to be taken long term?

The findings strengthen the idea that obesity should be treated as a chronic, relapsing condition, much like diabetes or hypertension. For many people, maintaining benefits may require long-term or even lifelong treatment, alongside broader lifestyle support.

 

Researchers also point out that drugs alone are unlikely to be the full solution. A more comprehensive approach, combining medication with nutrition, physical activity and long-term follow-up, may be needed to prevent rapid rebound.