Key points from article :
A major head-to-head clinical trial has found that Mounjaro (tirzepatide) leads to greater weight loss than its rival Wegovy (semaglutide), offering fresh insights into the evolving field of obesity treatments. The study, led by Dr. Louis Aronne of Weill Cornell Medicine and published in the New England Journal of Medicine, showed that after 72 weeks of treatment, participants on Mounjaro lost an average of 20% of their body weight, compared to 14% for those on Wegovy.
Both medications work by mimicking hormones that regulate appetite, helping users feel fuller and burn stored fat. However, Mounjaro appears more potent because it activates two appetite-regulating pathways in the brain, while Wegovy targets only one. In the trial involving 750 people with obesity, a third of those on Mounjaro lost at least 25% of their body weight, and they also saw greater reductions in waist circumference and improvements in blood pressure, blood sugar, and cholesterol. Side effects were similar across both drugs, and women tended to lose more weight than men.
Although both medications are available in the UK via specialist services or private prescriptions, Mounjaro’s stronger results are already driving higher private sales. However, Wegovy remains the only one so far approved for reducing the risk of heart attacks, with similar studies on Mounjaro still underway.
Experts like Prof Naveed Sattar of the University of Glasgow say both drugs are valuable tools in tackling obesity, though caution that broader societal efforts to promote healthy lifestyles remain essential. With ongoing research into new formulations and drugs, the field is rapidly advancing—and the ultimate “winner” in weight-loss medicine has yet to be decided.
