People who stop taking weight-loss drugs regain all of the weight initially lost in less than two years, significantly faster than those who follow any other weight-loss plan, according to a landmark study.
Weight-loss drugs known as GLP-1 agonists were originally developed to treat diabetes and work by mimicking the hormone glucagon-like peptide (GLP) 1, which helps people feel full.
studyconducted by scientists at the University of Oxford and published in the BMJ, included a review of 37 existing studies on weight-loss drugs, involving 9,341 participants. The mean duration of treatment for weight loss was 39 weeks, while the mean follow-up period was 32 weeks.
The analysis found that, on average, weight regained at a rate of 0.4 kg per month in people who stopped taking the medications, with participants returning to their original weight within an average of 1.7 years after stopping any type of weight-loss medication.
Specifically, people taking any weight-loss medication lost an average of 8.3 kg during treatment, but gained 4.8 kg during the first year.
The rate of weight regain after stopping these medications was nearly four times higher compared to behavioral programs, which may include a specific diet or physical activity plan, regardless of the amount of weight lost during treatment.
Dr Sam West from Nuffield Primary Care in Oxford Universitysaid that the rapid weight gain observed after stopping weight loss medications is not due to the medication itself.
“These drugs are revolutionizing the treatment of obesity and can provide significant weight loss. However, our research shows that people tend to gain weight quickly after they stop taking it—more quickly than we see with behavioral programs,” West said.
He added: “This is not a lack of medication – it reflects the nature of obesity as a chronic, relapsing disease. This sounds a cautionary note for short-term use without a more comprehensive approach to long-term weight control and highlights the importance of primary prevention.”
Previous research has shown that weight loss medications can also have beneficial effects on other areas of a patient's health, as shown in a study looking at drugs that could halve the risk of early death in patients with cardiovascular disease.
However, this study also found that the benefits of weight loss drugs on cardiometabolic health indicators such as blood pressure and cholesterol levels also returned to baseline levels within 1.4 years of stopping treatment.
Although previous studies have suggested that people weight loss drugs restore all the weight they lost during the year. stopping medication, this is the first study to show the rate of weight regain and the expected timing of weight and metabolic recovery.
Vegovi can be prescribed National Health Service for up to two years, and there is no statute of limitations for Munjaro.
'Weight-loss drugs can be effective tools for managing weight and the risk of type 2 diabetes, but this study confirms they are not a quick fix, according to Dr Fay Riley, head of research communications at Diabetes UK.
“They need to be prescribed appropriately, accompanied by individualized, comprehensive support, so that people can achieve full benefit and maintain weight loss for as long as possible after stopping the medication.”
Katherine Jenner, CEO Obesity The Health Alliance said that weight regain after stopping treatment is not the fault of individuals, but rather “reflects the reality of living in a food environment that continually pushes people toward unhealthy options.”
“These drugs may create a window of opportunity to improve the food environment at scale and pace—from the marketing of unhealthy foods to the accessibility and affordability of healthier foods—otherwise many people will struggle to maintain the health benefits of weight loss medications over the long term,” Jenner said.
An NHS spokesman said: “While these new treatments are an important new tool to support weight loss, they are not a magic bullet and must be combined with comprehensive behavioral and lifestyle support, including advice on healthier eating and physical activity, to maintain weight off in the long term.
“The NHS continues to introduce innovative ways to support people to lose weight safely and sustainably, and also offers a range of weight management services, including the NHS Digital Weight Management programme, which will be expanded to 125,000 people a year as part of the 10-year health plan.”
