People who stop using the weight-loss injection Mounjaro tend to regain lost weight and also lose key health improvements, including better blood pressure and lower “bad” cholesterol, according to new research.
The study analysed data from the Surmount-4 trial, where participants first took tirzepatide (the active drug in Mounjaro) for 36 weeks, then either continued the treatment or switched to a placebo. Among those who stopped the drug, 82% regained at least a quarter of the weight they had initially lost within a year.
Researchers found that weight regain was linked to a reversal in other benefits such as reduced waist size, improved cholesterol, and better blood sugar control. In those who regained most of the weight, health markers returned to pre-treatment levels.
Experts said the findings highlight the difficulty of maintaining long-term weight loss and the importance of ongoing treatment or lifestyle support. Some warned that stopping the medication may also remove potential heart-protection benefits seen in other studies.
The researchers concluded that long-term strategies are needed to maintain both weight loss and the broader health improvements linked to these medications.
