Adults taking Zepbound lost 47% more weight on average than those taking Wegovy, according to clinical trial data from drugmaker Eli Lilly.In a head-to-head comparison of the two GLP-1 drugs, adults living with obesity or overweight who were taking Zepbound, the brand name for tirzepatide, lost more than 20% of their weight on average after about a year and half, compared with an average of about 14% weight loss among those taking Wegovy, the brand name for semaglutide.That translates to an average weight loss of about 50 pounds for those taking Zepbound, compared with an average weight loss of 33 pounds for those taking Wegovy.People taking Zepbound were also more likely to reach specific weight loss targets than those taking Wegovy: About 32% of those taking Zepbound lost at least 25% of their body weight, compared with 16% of those taking Wegovy, Lilly said in a news release. The data have not yet been published in a peer-reviewed journal.Tirzepatide and semaglutide both mimic the effects of the gut hormone GLP-1, which stimulates the bodys production of insulin and slows the passage of food through the stomach. GLP-1 also signals the brain to help control appetite. Tirzepatide also stimulates a second gut hormone, called GIP, which may help boost its effects.The US Food and Drug Administration has approved versions of tirzepatide and semaglutide to treat both type 2 diabetes and obesity. Eli Lilly manufactures tirzepatide under the brand name Mounjaro for diabetes and Zepbound for chronic weight management, while Novo Nordisk manufacturers semaglutide as Ozempic for diabetes and Wegovy for weight management.Given the increased interest around obesity medications, we conducted this study to help health care providers and patients make informed decisions about treatment choice, Dr. Leonard C. Glass, senior vice president of global medical affairs at Lilly Cardiometabolic Health, said in a statement on Wednesday. Zepbound is in a class of its own as the only FDA-approved dual GIP and GLP-1 receptor agonist obesity medication, and its changing how millions of people manage this chronic disease.The new clinical trial data from Lilly echoes findings from earlier research based on electronic health records comparing outcomes for those taking tirzepatide and semaglutide. However, earlier research included some data from individuals living with both obesity and diabetes. The 751 participants in the Lilly trial did not have diabetes; instead, the trial focused on adults living with obesity or overweight who have at least one other comorbidity, hypertension, dyslipidemia, obstructive sleep apnea (OSA) or cardiovascular disease.The most commonly reported side effects among those taking both Zepbound and Wegovy were mild to moderate gastrointestinal symptoms, Lilly said.The drugmaker plans to publish the results from this clinical trial in a peer-reviewed journal and present at a medical meeting next year.