People who stop using the weight-loss injection Mounjaro tend to regain weight and lose key health improvements, including lower “bad” cholesterol, improved blood pressure and better blood sugar control, according to new research.
The findings come from the Surmount-4 clinical trial, in which participants with obesity or weight-related health conditions took tirzepatide (the active ingredient in Mounjaro) for 36 weeks, then either continued treatment or switched to a placebo for a further year.
Among those who stopped the drug after initially losing at least 10% of their body weight, 82% regained at least a quarter of the lost weight within a year. Greater weight regain was also linked to reversal of improvements in cholesterol levels, waist size, blood pressure and glucose control.
Researchers concluded that long-term treatment and sustained lifestyle changes may be necessary to maintain both weight loss and cardiometabolic benefits. Separate research also suggested that stopping weight-loss drugs before or during pregnancy may be linked to increased risks, although experts cautioned more studies are needed to confirm cause and effect.
