Weight lost with Ozempic often returns within two years, study finds

A new study published in The British Medical Journal (The BMJ) warns that weight lost through obesity drugs like Ozempic is typically regained within an average of 1.7 years after stopping treatment, reports Finnish public broadcaster Yle.

The analysis of 37 studies involving over 9,300 participants found that while medications mimicking intestinal hormones—such as Ozempic’s active ingredient, semaglutide—effectively reduce weight and improve cardiovascular and metabolic health, these benefits diminish rapidly once treatment ends. On average, patients regained weight at a rate of 0.4 kg per month after discontinuing the drug, returning to their original weight within 1.7 years. By comparison, those who stopped lifestyle intervention programs regained weight more slowly, reaching their starting point only after 3.9 years.

Pia Pajunen, a specialist physician at Finland’s Social Insurance Institution (Kela), emphasised that obesity is a lifestyle-related condition requiring long-term behavioural changes rather than relying solely on medication. “Drug therapy should only support lifestyle treatment, not replace it,” she told Yle. She also cautioned that all medications carry risks, including common side effects like nausea, vomiting, diarrhoea, and constipation—affecting more than one in ten users—as well as rarer but severe complications such as acute pancreatitis (1 in 100) or a serious eye condition called NAION (1 in 10,000).

Kati Myllymäki, chair of Finland’s National Advisory Board on Social Welfare and Health Care Ethics, noted that modern society’s reduced physical activity and high-calorie diets make maintaining a healthy weight difficult. Genetics also play a significant role, influencing 40–70% of an individual’s ability to stay at a normal weight. Evolutionary biology further complicates weight loss, as the body naturally resists lowering its highest recorded weight—a survival mechanism from times when food was scarce.

Obesity is clinically defined by a body mass index (BMI) of 30 or higher, though waist circumference (over 100 cm for men, 90 cm for women) can also indicate unhealthy fat distribution. Experts warn against short-term use of obesity drugs without a comprehensive, sustainable plan for weight management.