Study examines yo-yo effectWithout a weight loss injection, body weight increases rapidly again
09.01.2026, 17:31 Clock
Listen to article(04:11 min)
Anyone who stops taking weight loss injections like Ozempic will regain weight four times faster than with conventional diets with exercise and changes in diet. Within a year, almost all the pounds lost return, a study shows. Experts therefore warn of long-term risks.
According to a study, when losing weight with injections like Ozempic, the dreaded yo-yo effect is particularly strong: those who stop the treatment gain weight again four times faster than after diet programs with a change in diet and more exercise. According to the study published in the British Medical Journal, this is primarily because the weight loss caused by weight loss injections is particularly strong.
So-called GLP-1 drugs such as the weight loss injections Ozempic and Wegovy are used to treat type 2 diabetes and to help overweight and obese patients lose weight. They regulate blood sugar levels and increase the feeling of satiety. According to clinical studies, patients lose an average of 15 to 20 percent of their body weight.
“All of this seems like good news,” said Oxford University nutritionist Susan Jebb, who was involved in the new study. According to them, around half of the patients stop taking the medication within a year, which could be due to widespread side effects such as nausea or the high costs: In the USA, the treatment costs more than 1000 dollars (around 850 euros) per month.
Around 0.4 kilograms return per month
Jebb and her colleagues now evaluated 37 clinical studies that looked at various weight loss medications. They found that the patients gained weight again after stopping the medication – an average of around 0.4 kilograms per month.
Six of the studies evaluated examined the active ingredients of the drugs Ozempic and Wegovy from the Danish manufacturer Novo Nordisk and Mounjaro and Zepbound from the US manufacturer Eli Lilly, semaglutide and tirzepatide. While taking these medications, the patients lost an average of almost 15 kilograms in weight. After stopping the medication, they gained ten kilograms again within a year.
Longer-term data is not yet available. However, the researchers assume that the patients will return to their original weight after 18 months. After 1.4 years, blood pressure and cholesterol levels were also as high as they were at the start of treatment.
According to the study, patients who took part in diet and exercise programs instead lost significantly less weight. However, it took an average of four years for them to gain back the pounds they had lost.
Big weight loss, rapid weight gain
“Greater weight loss tends to lead to faster weight gain,” explained study leader Sam West from the University of Oxford. After taking medication, weight gain occurs “invariably faster, regardless of the weight previously lost.” He suspects that people who have learned to eat healthier and exercise more will at least partially maintain this behavior even after their diet ends.
GLP-1 drugs are “really useful” in the treatment of obesity, said co-author Jebb, summarizing the results of the study. In order to maintain the new weight in the long term, the patients would probably have to take the medication permanently.
The new study makes it clear that weight loss injections are only the beginning of therapy, but “not a cure,” added metabolism expert Garron Dodd from Melbourne, who was not involved in the study.