A new study has found that people who stop using the weight-loss jab Mounjaro not only tend to regain weight but also lose other health benefits, such as reduced blood pressure and lower levels of 'bad' cholesterol. The findings, published in JAMA Internal Medicine, raise questions about the long-term value of such medications.
The research analysed data from the Surmount-4 clinical trial, which involved participants with obesity or overweight who had at least one weight-related health problem. All participants received tirzepatide, the active ingredient in Mounjaro, for 36 weeks, along with diet and exercise support. They were then randomly split into two groups: one continued the medication for another 52 weeks, while the other switched to a placebo.
Among 308 participants who had lost at least 10% of their body weight by the end of the initial 36-week period and then switched to the placebo, 82% regained 25% or more of their initial weight loss after one year. The team found that greater weight regain was associated with a reversal of improvements in waist circumference, 'bad' cholesterol, blood pressure, and blood glucose levels.
Professor Naveed Sattar of the University of Glasgow said the findings were not surprising, as excess weight is a known driver of elevated blood pressure and impaired glucose control. He noted that when weight is regained, these risk factors typically rise in proportion to the speed and extent of weight regain. He added that stopping the drugs could also remove a protective effect against heart failure and death.
Professor Jane Ogden of the University of Surrey commented that weight-loss jabs do not always create healthier eating and exercise habits, and can sometimes lead to poorer diets as people lose motivation. She said that when people stop taking the medication, they return to previous behaviours, leading to weight regain and a reversal of cardiac benefits.
