New oral weight-loss pill under study

ScienceAlert on May 20 highlighted a new study on orforglipron, Eli Lilly’s once-daily oral GLP-1 drug, as researchers test whether a pill can help patients hold onto weight loss after injectable treatments. The study it cited was published May 12 in *Nature Medicine* and presented at the European Congress on Obesity in Istanbul. The trial examined people who had already lost substantial weight on injectable GLP-1 drugs and then switched to oral orforglipron. The results add to a fast-moving obesity-drug market in which manufacturers are trying to offer alternatives to weekly injections. ### Which pill is at the center of this study? Orforglipron is Lilly’s oral small-molecule GLP-1 receptor agonist, and in the United States it is sold under the brand name Foundayo. Unlike peptide-based GLP-1 drugs such as Wegovy and Mounjaro, the pill is designed as a small molecule that can be taken orally rather than injected. ScienceAlert, republishing a Conversation article by Simon Cork, said that feature could reduce some of the barriers tied to injections, including storage and device costs. (sciencealert.com) Lilly said on April 1 that the U.S. Food and Drug Administration approved Foundayo for adults with obesity, or overweight with weight-related medical problems. The company said shipping would begin April 6, with broader retail availability to follow. ### What exactly did the new study test? (sciencealert.com) The ATTAIN-MAINTAIN trial studied whether patients who had already lost weight on injectable semaglutide or tirzepatide could maintain that reduction after switching to daily oral orforglipron. Weill Cornell Medicine said the phase 3b trial was led by investigators from Weill Cornell and NewYork-Presbyterian and was sponsored by Lilly, which makes both orforglipron and tirzepatide. (investor.lilly.com) Nature Medicine described the study as a double-blind, randomized phase 3b trial. Weill Cornell said 205 patients who had taken tirzepatide and 171 who had taken semaglutide were randomized to receive orforglipron or placebo daily for a year after their earlier weight loss had plateaued. ### What did researchers find? Weill Cornell said patients who switched to once-daily orforglipron maintained about 75% to 80% of their prior weight loss and preserved related cardiometabolic benefits, including improvements in waist circumference, blood pressure, blood sugar, triglycerides and cholesterol. (news.weill.cornell.edu) The institution said gastrointestinal side effects were generally mild to moderate. (nature.com) Dr. Louis J. Aronne of Weill Cornell, the study’s lead author, said in the institution’s release that the trial was “the first study of its type” to test longer-term maintenance with an oral GLP-1 after injectable treatment. ScienceAlert’s account framed the study around a persistent problem in obesity treatment: patients often regain weight after stopping injectable drugs. (news.weill.cornell.edu) ### How does this fit with earlier data on the drug? Lilly reported in August 2025 that ATTAIN-1, one of its pivotal obesity trials, showed average weight loss of 12.4% at 72 weeks on the highest dose of investigational orforglipron versus 0.9% with placebo. The company said at the time that the oral drug had met the primary endpoint and key secondary endpoints in adults with obesity or overweight without diabetes. (news.weill.cornell.edu) ScienceAlert said oral orforglipron could offer a cheaper and more convenient option than injectable drugs, citing U.S. monthly pricing of $149 to $299 for the pill versus more than $1,000 for Mounjaro. That comparison came in a report published after FDA approval, not in the new maintenance trial itself. (investor.lilly.com) ### What should readers be careful not to overstate? Nature Medicine published the maintenance study on May 12, but the findings apply to a specific use case: patients who first lost weight on injectable GLP-1 drugs and then switched to oral treatment. The study does not show that an oral pill eliminates the need for long-term therapy, and Weill Cornell said patients maintained most, but not all, of their earlier weight loss. (sciencealert.com) April 1 remains the key regulatory date for the pill in the United States, while May 12 is the publication date for the maintenance data in *Nature Medicine*. Lilly’s next public milestones are likely to come through additional commercial rollout updates and any future trial disclosures tied to broader use of Foundayo. (investor.lilly.com) (nature.com)