- A new analysis suggests many people regain a large share of the weight lost on GLP-1 drugs within a year of stopping treatment.
- The regain appears to happen fastest in the first few months, before slowing over time.
- The findings reinforce that obesity often needs long term management, not just short term treatment.
GLP-1 drugs such as semaglutide, liraglutide and tirzepatide have changed the treatment of obesity.
They can help people lose a significant amount of weight, often in the region of 15% to 20% of their starting weight.
That level of weight loss can improve health risks linked to obesity, including cardiometabolic disease.
But a new study suggests that keeping the weight off after stopping treatment may be much harder.
Researchers analysed data from studies looking at what happened after people came off GLP-1 treatment.
They found a clear pattern of weight regain after treatment ended.
The model suggested that people regained around 60% of the weight they had lost within a year of stopping.
Most of that regain happened early, with the pace slowing as time went on.
Overall, the researchers estimated that weight regain eventually levels off at around 75% of the weight originally lost.
That means some benefit may remain after stopping, but much less than during treatment.
The main analysis was based on six randomised controlled trials involving 3,236 participants.
In total, the wider review included 48 studies involving overweight or obese adults.
The study also looked at other measures such as HbA1c and systolic blood pressure.
HbA1c improved during treatment, but around half of that improvement had been lost within 8 to 12 weeks of stopping.
Even so, HbA1c generally remained below starting levels at one year.
A few studies suggested that some strategies may help limit regain.
These included gradual dose tapering, a low carbohydrate diet after stopping, and possibly staying on treatment for longer.
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However, the evidence on those approaches is still limited.
The researchers also pointed out that many of the studies had a moderate risk of bias.
Another important limitation is that the available follow-up data did not go much beyond one year, so some of the longer term estimates were modelled rather than directly measured.
Even with those caveats, the message is straightforward.
For many people, stopping GLP-1 treatment is followed by weight regain, and that needs to be part of the conversation from the start.
This supports a more flexible and individual approach to obesity care.
For some people, that may mean longer treatment, slower withdrawal, or stronger support around food, activity and behaviour change after stopping.
Journal reference: Budini B, Luo S, Tam M, et al. Trajectory of weight regain after cessation of GLP-1 receptor agonists: a systematic review and nonlinear meta-regression. eClinicalMedicine. 2026.
