Do Wegovy and Mounjaro work the same? The injection that aims to end obesity faster.

Since 1990, obesity has doubled among adults worldwide and quadrupled among adolescents. It is a public health problem that concerns health authorities, and in 2022, the WHO estimated that one in eight people suffered from it.

The phenomenon of anti-obesity drugs arrived a few years ago, specifically, in 2017 , the American agency in charge of regulating drugs (FDA) approved the use of semaglutide, better known as Ozempic . This drug marked a before and after in the treatment of diabetes. However, it soon became a weapon to fight excess weight, since it acts as an appetite suppressant. Semaglutide, the name of the drug, mimics the action of the GLP-1 hormone produced in the intestine and acts in the brain , regulating satiety and the desire to eat.

Ozempic was followed by others such as Mounjaro (tirzepatide), from the Eli Lilly company, and Wegovy, from Novo Nordisk. A new study was published this Monday in The New England Journal of Medicine , comparing tirzepatide with semaglutide. This is a 72-week, open-label, Phase 3b SURMOUNT-5 trial comparing the use of both injections in American adults with obesity or overweight. Not only that, the 751 participants also suffer from at least one of the following comorbidities: high blood pressure, dyslipidemia, obstructive sleep apnea (OSA), or cardiovascular disease, and no diabetes.

With tirzepatide, 89.3% received at least one 15 mg dose , and with semaglutide, 92.8% received 2.4 mg. Thus, the primary objective of the study is to demonstrate the superiority of tirzepatide over semaglutide in percentage change in body weight from baseline to 72 weeks.

The analysis is being published to coincide with the European Congress on Obesity , taking place from May 11 to 14 in Malaga. For the primary endpoint, average weight loss percentage, participants treated with Mounjaro achieved an average weight loss of 20.2%, while those treated with Wegovy achieved a 13.7% reduction. This represents a 47% greater relative weight loss, with the former losing an average of 22.8 kg and those treated with semaglutide losing an average of 15 kg.

Across key secondary endpoints , Lilly's drug was superior across all weight-loss objectives , with 64.6% of participants achieving at least a 15% weight loss and 40.1% of those on semaglutide achieving at least a 15% weight loss. For greater waist circumference reduction , the figures were 18.4 and 13 centimeters, respectively.

For his part, Louis J. Aronne is familiar with the trial, as its senior author. He also serves as director of the Comprehensive Weight Management Center and the Sanford I. Weill Professor of Metabolic Research at Weill Cornell Medicine, among others. "Thanks to the latest advances in obesity management medications , an increasing number of physicians and patients are seeing greater degrees of weight loss than they had previously seen," he explains.

"The results of SURMOUNT-5 have demonstrated that tirzepatide leads to greater weight reduction compared with semaglutide, providing further evidence to support it as an effective option for obesity management ," he concludes.