The U.S. Food and Drug Administration’s approval of Eli Lilly’s once-daily pill orforglipron as a weight loss and obesity treatment this week was the fastest approval of a new medication in decades. Clinical trial results showed that the highest doses of the oral medication, which will be marketed as Foundayo, caused people to lose an average of 27 pounds after 72 weeks of treatment.
The new oral medication is the latest glucagonlike peptide 1 (GLP-1) drug in the rapidly expanding market. Foundayo is the second GLP-1 weight-loss pill to gain FDA approval; Novo Nordisk’s once-a-day Wegovy pill was approved in December 2025. Experts hope that having more options for these popular weight-loss and type 2 diabetes treatments will drive down costs and offer people more flexibility.
“Generally it’s much easier to make pills and distribute them,” compared with injectable drugs, says Daniel Drucker, an endocrinologist at the University of Toronto, who has previously consulted for Eli Lilly. “That should be an advantage in really getting the drug to a much wider population.”
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In the latest phase 3 trial of orforglipron, three doses of the drug were compared with a placebo in 1,613 people with type 2 diabetes who were overweight or had obesity. After 72 weeks, people on the six-milligram dose lost 5 percent of their body weight, those on 12 milligrams lost 7 percent, and those on 36 milligrams lost nearly 10 percent.
A clinical trial found a 25-mg dose of the Wegovy pill caused nearly 17 percent weight loss in 64 weeks. And in another clinical trial, injections of 15-mg doses of tirzepatide (the active ingredient in Eli Lilly’s weight-loss injectable Zepbound) resulted in an average of about 21 percent body-weight reductions after 72 weeks.
“It’s not as high of weight loss as tirzepatide and not as high as some of the things that we’ll see coming down the pipeline in the next six months to a year, but I think there’s room for all of those [medications],” says Deborah Horn, director of obesity medicine at UTHealth Houston, who led the most recent trial on Foundayo. (Horn consults for Eli Lilly.)
The various forms and levels of effectiveness of these drugs could provide more individualized treatments, she says. For instance, another recently completed trial by Eli Lilly investigated if people who were initially treated with an injectable GLP-1 drug could eventually transition to an oral version like Foundayo and still maintain the weight loss and health benefits. The results have been submitted for peer-reviewed publication.
“A lot of people are asking the question: ‘If I do these injectables for a year and get to a healthy place, could I transition to this oral medication and keep the weight off?’” Horn says. “That data will be available very soon.”
Foundayo works similarly to other GLP-1 drugs, such as semaglutide—the active ingredient in the injectable and pill forms of Wegovy. The new oral drug latches on to the receptors for the gut hormone GLP-1 to make people feel satiated and slow down stomach emptying, causing them to eat less and ultimately lose weight. The Wegovy pill and all currently available injectable versions of the drug are peptides, or short chains of amino acids, that are similar to the body’s GLP-1, whereas Foundayo is a nonpeptide small molecule. That comes with several advantages, Horn says.
Because Semaglutide is a peptide, it quickly degrades in the acidic environment of our stomach, Horn explains. The Wegovy pill has a special ingredient that shields it from some erosion, but people must still take it on an empty stomach to ensure it’s properly absorbed. As a nonpeptide, Foundayo can be absorbed through the gut without breaking down, and that means it can be taken anytime, regardless of when you eat, drink or take other medications.
Such small-molecule-based drugs are also generally easier and cheaper to manufacturer than peptides. “In terms of distribution, it gets rid of things like cold storage and plastics for [injection] pens,” Horn says.
In a press release about Foundayo’s approval, Eli Lilly listed the starting price for the drug at $25 per month for people who have commercial insurance and enroll in the company’s Foundayo savings card program. Out-of-pocket costs start at $149 per month and go up to $349 for higher doses, according to material an Eli Lilly spokesperson shared with Scientific American. Starting in July, the drug is expected to be available for $50 to eligible individuals on Medicare Part D—a federal prescription drug benefit program for adults who are aged 65 and older or have certain disabilities.
Eli Lilly’s announcement lists several tablet doses, starting at 0.8 mg and up to 17.2 mg—the pill with the maximum dosage of 17.2 mg is reported have an efficacy equivalent to the 36-mg dose tested in trials, according to the company spokesperson. Further information isn’t yet publicly available on the pricing of the various doses. The FDA’s news release about the approval describes a schedule that gradually increases doses over time—a titration scheme similar to that of other GLP-1 drugs that helps the body adjust to the medication, Drucker explains. “We’ve seen with every single one, if you start too high and increase the dose too quickly, you get sick,” he says.
Similar to other GLP-1 medications, Foundayo causes nausea, vomiting, diarrhea and other gastrointestinal side effects. In the recent trial, participants on the highest 36-milligram dose had about a 2 percent greater risk of a serious adverse event, compared with those given a placebo. Rates of treatment discontinuation—most commonly from gastrointestinal symptoms—were higher, at 6 to 10 percent, depending on the dose, for those who received the pill, compared with a rate of 4 percent for those who received the placebo. The trials find Foundayo to be very safe, but Drucker notes that people should continue to keep a watchful eye on any new drug.
For peptide-based GLP-1 drugs, “we have 21 years of safety data,” he says. “Whenever we have a new medicine, we always restart the clock in terms of safety.”
In a response to Scientific American’s request for comment, the Eli Lilly spokesperson said that the FDA reviewed the company’s “robust clinical data package” and that the approval establishes “Foundayo’s strong safety and efficacy profile.”
Foundayo and other weight-loss drug candidates in the works could increase supply and help with affordability of GLP-1 drugs overall—though that might take some time, Horn says. “I don’t think we’re at very, very inexpensive yet, but I think we will get there as more and more GLP-1s and other medicines become available.”
Editor’s Note (4/2/26): This article was updated after posting to include comments from a spokesperson for Eli Lilly.