People who stop using the weight-loss drug Mounjaro (tirzepatide) not only tend to regain lost weight but also lose key health benefits, according to new research.
The study, based on the Surmount-4 clinical trial, found that stopping the medication led to rising blood pressure, worsening cholesterol levels and poorer blood sugar control. Experts say this is largely driven by weight regain, which reverses earlier improvements in heart and metabolic health.
All participants in the trial initially took tirzepatide for 36 weeks. They were then split into two groups: one continued the drug for another year, while the other switched to a placebo. Among those who stopped the treatment, 82% regained at least 25% of their original weight loss within a year.
Researchers found that the more weight participants regained, the more their health markers — including waist size, “bad” cholesterol, blood pressure and blood glucose — returned to their original levels. Those who regained most of their weight saw their cardiometabolic health fully revert to baseline.
Experts say the findings highlight the importance of long-term weight management strategies. Professor Naveed Sattar of the University of Glasgow noted that stopping the drug may also remove protective effects against heart failure and early death seen in other studies.
Researchers added that weight-loss injections don’t always build long-term healthy eating and exercise habits, which may explain why many people struggle after stopping them.
Separate research also suggests that women who stop such medications before or during early pregnancy may face higher risks of complications, although experts caution that more research is needed to confirm any direct cause.
