Eli Lilly and Co. announced on Thursday that its experimental obesity drug retatrutide achieved up to 28.3 percent body-weight reduction over 80 weeks in the pivotal Phase 3 TRIUMPH-1 trial — a result approaching the threshold long associated with bariatric surgery — and topping the weight-loss numbers of every drug currently on the market. That exceeds the roughly 15 percent weight loss seen with semaglutide (Wegovy) at 68 weeks and the 21 percent seen with tirzepatide (Zepbound) at 72 weeks in their respective Phase 3 trials, though cross-trial comparisons are limited.
Patients on the highest dose of 12 milligrams once weekly lost an average of 70.3 pounds at week 80, against 5.5 pounds for placebo, the company said in a release. The 9 mg arm achieved 25.9 percent weight loss; the 4 mg arm 19.0 percent. In a pre-specified blinded extension to 104 weeks for participants with baseline body-mass index of 35 or higher, the 12 mg group reached 30.3 percent weight loss, or 85.0 pounds on average. Some 45.3 percent of patients on the top dose lost at least 30 percent of body weight, a threshold the company described as “long associated with bariatric surgery.”
Retatrutide is the first investigational molecule to target the GIP, GLP-1 and glucagon hormone receptors simultaneously, going one receptor further than Lilly’s own approved Mounjaro and Zepbound. Lead investigator Ania Jastreboff of the Yale School of Medicine said “It was impressive to see that every dose of retatrutide resulted in clinically meaningful weight reduction for nearly all participants.” Kenneth Custer, Lilly’s cardiometabolic-health chief, said “TRIUMPH-1 highlights the importance of options and the potential for retatrutide to help people across various stages.”
Side-effect rates were higher than placebo across all doses, with up to 42.4 percent of 12 mg patients reporting nausea. Discontinuation due to adverse events ranged from 4.1 to 11.3 percent versus 4.9 percent for placebo. These are topline Phase 3 results; full data are scheduled for presentation at the American Diabetes Association Scientific Sessions and publication in peer-reviewed journals.
For Filipino patients, retatrutide remains unavailable outside clinical trials. Pharmacy Times has reported that a regulatory submission is anticipated in 2026, with U.S. approval and launch timelines described differently across outlets. Philippine availability would likely follow later, subject to local FDA review, pricing, and supply.
