Key points from article :
A new analysis of data from the Surmount-4 clinical trial, published in JAMA Internal Medicine, shows that people who stop taking the weight-loss drug Mounjaro (tirzepatide) not only regain the weight they lost, but also lose the broader health benefits gained during treatment. The study was conducted by researchers including scientists from Eli Lilly, the drug’s manufacturer. Tirzepatide has become widely used because it can help people lose around 20% of their body weight over 72 weeks, but earlier research has already shown that stopping the medication often leads to substantial weight regain.
In this latest analysis, the team examined 308 participants who had lost at least 10% of their body weight after 36 weeks of tirzepatide alongside diet and exercise support. Half of the group then continued the drug for another 52 weeks, while the others unknowingly switched to a placebo. One year after stopping tirzepatide, 82% of those in the placebo group had regained at least a quarter of the weight they had initially lost. The degree of weight regain strongly correlated with the return of earlier health issues: increases in waist circumference, higher levels of LDL (“bad”) cholesterol, elevated blood pressure, and rising blood glucose levels. Participants who regained three-quarters or more of their lost weight saw almost all cardiometabolic markers return to their original baseline.
Experts note that the results are expected because excess weight is closely tied to poorer cardiometabolic health. When weight returns, so do associated risks—including the potential loss of protective effects against heart failure and death that have been linked to drugs like tirzepatide. Behaviour may also play a role; some people rely on weight-loss injections without developing healthier eating and exercise habits, making relapse more likely when treatment ends.
The findings underscore that long-term weight management may require ongoing medication, along with sustained lifestyle changes, to preserve benefits. Additional research also hints at possible risks for women who discontinue these drugs before or during pregnancy, though experts caution that these observational findings require more robust clinical trials before firm conclusions can be drawn.
