Lilly's new experimental shot produced 28% weight loss

By Jaimy Lee The injection is different than Zepbound and Foundayo. It includes GIP, GLP-1, and glucagon A view of the New York Stock Exchange after Eli Lilly's team rang the opening bell in New York on May 11. (Photo by ANGELA WEISS / AFP via Getty Images) Eli Lilly's next-generation weekly weight-loss shot may be more effective than bariatric surgery, which has long been the gold standard for weight loss. In a Phase 3 trial, which is called TRIUMPH-1, participants took 4 mg, 9 mg or 12 mg of Lilly's retatrutide for about a year and a half. People taking the highest dose lost 28.3% of their body weight, while nearly half of the participants lost more than 30% of their body weight. Those taking the lowest dose still lost 19.0% of their body weight. The study's results are the latest signal that retatrutide may be the most effective weight-loss medication in development. As such, retatrutide is a highly anticipated addition to Lilly's (LLY) obesity portfolio, which already includes Zepbound, a weekly GLP-1/GIP shot, and Foundayo, a daily non-peptide GLP-1 pill. It is sometimes referred to as "triple G" because it includes GIP, GLP-1, and glucagon. "Retatrutide could build on Lilly's commitment to match treatments to the needs and preferences of patients," said Kenneth Custer, president of Lilly Cardiometabolic Health, in a statement. The still-experimental injection has largely been viewed as a therapy that would work best in people with severe obesity, and Lilly noted that the amount of weight loss is on par with what patients see after getting bariatric surgery. People taking retatrutide in the trial experienced similar side effects that are common with other GLP-1 medications. Between 28.6% and 42.4% of participants reported nausea, depending on their dose, and between 25.3% and 32.0% reported diarrhea. About 11% of patients taking the high dose of retatrutide stopped participating in the trial as a result of the side effects. Among so-called peptide users, often people involved in the fitness or looksmaxxing communities, off-label use of retatrutide has become popular. People purchase the raw ingredients and then mix and inject them themselves. -Jaimy Lee This content was created by MarketWatch, which is operated by Dow Jones & Co. MarketWatch is published independently from Dow Jones Newswires and The Wall Street Journal. (END) Dow Jones Newswires 05-21-26 0811ET