Weight‑loss drugs such as Ozempic and Wegovy have become widely known in recent years because they can help people lose a large amount of weight. These medicines work by affecting a hormone in the body that controls hunger and blood sugar.
Many people who take them feel full sooner, eat less food, and gradually lose weight. Clinical studies have shown that these drugs can lead to weight loss of about 15% to 20% of a person’s body weight, which is much more than most traditional weight‑loss medications.
However, an important question has remained unclear: what happens after people stop taking these medications?
A new study from researchers at the University of Cambridge offers some answers. The research, published in the medical journal eClinicalMedicine, suggests that people tend to regain much of the weight they lost after stopping the drugs, but not all of it.
Obesity is a major global health problem. More than one billion people worldwide are living with obesity, according to recent estimates. Excess body weight increases the risk of many serious health conditions, including type 2 diabetes, heart disease, stroke, and some types of cancer. Losing weight can significantly reduce these risks and improve overall health.
Unfortunately, losing weight through diet and exercise alone can be very difficult for many people, especially when the body naturally tries to regain lost weight.
Because of this challenge, a new generation of medicines has changed the way doctors treat obesity. Drugs such as Ozempic and Wegovy belong to a group called GLP‑1 receptor agonists.
These medications mimic a natural hormone known as glucagon‑like peptide‑1, which helps regulate blood sugar levels and signals the brain that the body is full. By strengthening this signal, the drugs reduce appetite and help people eat smaller portions.
Although these drugs can be very effective, many people do not stay on them long term. Studies show that about half of patients stop taking them within the first year. After two years, about three‑quarters of patients have discontinued treatment.
There are several reasons for this. Some people experience side effects such as nausea or stomach discomfort. Others stop because of the high cost of the drugs or because insurance coverage is limited in many healthcare systems.
The research team at the University of Cambridge wanted to understand what happens after people stop taking these medications. To investigate this, they reviewed and combined results from many previous studies on GLP‑1 weight‑loss drugs.
First, they conducted a systematic review, which means they carefully searched scientific databases to find all relevant studies. Then they carried out a meta‑analysis, a method that combines results from multiple studies to estimate overall trends more reliably.
In total, the researchers examined 48 studies that included data on weight loss drugs targeting the GLP‑1 receptor. These studies included 36 randomized controlled trials, which are considered the gold standard for clinical research, and 12 additional studies with other designs.
Many of the studies followed patients only for a short time after they stopped taking the medication. To obtain more reliable long‑term estimates, the researchers focused on six high‑quality trials that followed more than 3,200 patients for up to one year after stopping treatment.
Using these data, the researchers built a statistical model to estimate how body weight changes over time after people discontinue the drugs. Their model showed that weight regain happens quickly at first. During the first year after stopping treatment, patients regained about 60% of the weight they had originally lost.
After this initial period, however, the rate of weight regain slowed down. Around 60 weeks after stopping the medication, weight gain began to level off.
The model predicted that weight regain would eventually stop at about 75% of the original weight loss. In other words, people were still able to maintain roughly 25% of the weight they lost during treatment.
For example, if someone lost 20% of their body weight while taking the medication, the long‑term result might still be a weight loss of about 5% even after stopping the drug. Although this is much less than the original loss, it still represents a meaningful improvement in body weight and health risk.
The researchers also found that weight regain patterns appeared similar for different types of GLP‑1 drugs. This suggests the effect is related to the general way these medicines influence appetite and metabolism rather than to a specific drug.
Scientists believe several factors may explain why some weight loss remains even after treatment ends.
During treatment, people often develop new eating habits because they feel full more quickly and naturally eat smaller portions. Some of these habits may continue after the medication is stopped. In addition, the drugs may cause longer‑lasting changes in the brain systems that control appetite.
However, the researchers also raised an important concern. Previous studies have shown that a significant portion of the weight lost during treatment may come from lean body mass, which includes muscle. Some estimates suggest that 40% or more of weight loss could be muscle rather than fat.
The current study could not determine whether the weight people regain after stopping the drugs consists mostly of fat or whether muscle mass also returns. If the regained weight is mainly fat while muscle remains reduced, the overall body composition could actually become less healthy. This is an important issue that future research will need to explore.
The study also has limitations. Most importantly, the clinical trials used to build the model only followed participants for about one year after they stopped taking the drugs.
The researchers had to use statistical methods to estimate what might happen after that time. In addition, the analysis included only studies where participants lost at least three kilograms during treatment.
Despite these limitations, the findings provide valuable insight into the long‑term effects of modern weight‑loss medications. The results suggest that while weight regain is common after stopping GLP‑1 drugs, some of the weight loss may remain, particularly if people maintain healthy eating and exercise habits.
Study analysis and interpretation: This research highlights both the benefits and limitations of current weight‑loss medications. The study’s strength lies in its use of data from many clinical trials and its effort to model long‑term trends after treatment ends.
However, because the results rely partly on projections rather than long‑term real‑world observations, more studies following patients for several years will be needed to confirm the conclusions.
The findings also emphasize that medication alone is unlikely to provide a permanent solution to obesity. Long‑term success will likely depend on combining medical treatment with lifestyle support, including improved diet, physical activity, and behavioral changes.
If you care about weight loss, please read studies about orange that could help obesity, and a berry that can prevent cancer, diabetes and obesity.
For more health information, please see recent studies about ginger’s journey in weight management ,and green tea: a cup of weight loss.
The research findings were published in eClinicalMedicine.
Copyright © 2026 Knowridge Science Report. All rights reserved.
