Foundayo (orforglipron): FDA approval, pivotal trial and safety
Approved
Type
New molecular entity · Oral
FDA-approved use
To reduce excess body weight and maintain weight reduction long term in adults with obesity or adults with overweight in the presence of at least one weight-related comorbid condition, in combination with a reduced-calorie diet and increased physical activityWording from FDA's list of novel approvals.
FDA review
Standard review
Company
Eli Lilly
Application
NDA 220934
Specialty
Endocrinology
Boxed warning: Risk of thyroid C-cell tumors
At a glance
Foundayo is the first oral small-molecule GLP-1 receptor agonist, approved for chronic weight management in adults with obesity, or overweight with a weight-related condition. In ATTAIN-1, the highest dose produced an 11.2% mean weight loss at 72 weeks versus 2.1% with placebo, and more than half of patients lost at least 10% of their weight. Like injectable GLP-1 drugs, it carries a boxed warning for thyroid C-cell tumors.
What it is and how it works
Orforglipron activates the GLP-1 receptor, including receptors in brain regions that regulate appetite, reducing hunger and food intake. Unlike semaglutide tablets, it is not a peptide but a small molecule designed to be absorbed by mouth.
Phase 3, multinational, randomized (3:3:3:4), double-blind, placebo-controlled, 72 weeks; three doses or placebo, with diet and physical activity counseling.
Patients
3,127 adults with obesity (or overweight with a weight-related condition) without diabetes.
Compared with
Placebo
Primary endpoint
Percent change in body weight from baseline to week 72 (treatment-regimen estimand).
Result
Mean weight change -7.5%, -8.4% and -11.2% with the three doses versus -2.1% with placebo (P<0.001 for all). With the highest dose, 54.6% lost at least 10%, 36.0% at least 15% and 18.4% at least 20%, versus 12.9%, 5.9% and 2.8% with placebo.
Other results
Waist circumference, systolic blood pressure, triglycerides and non-HDL cholesterol all improved significantly versus placebo.
Safety in the trial
Discontinuation for adverse events 5.3% to 10.3% versus 2.7%; mostly mild to moderate gastrointestinal effects.
How does Foundayo (orforglipron) compare with the alternatives (Tirzepatide, Semaglutide injection, Oral semaglutide for weight management) for its approved use (to reduce excess body weight and maintain weight reduction long term in adults with obesity or adults with overweight in the presence of at least one weight-related comorbid condition, in combination w…? Summarize head-to-head and indirect evidence, efficacy, safety and where each fits, with citations.
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Safety signals
Gastrointestinal effects were the most common adverse events and were mostly mild to moderate. Adverse events led to stopping treatment in 5.3% to 10.3% of patients on orforglipron versus 2.7% on placebo. The boxed warning on thyroid C-cell tumors, seen in rodents with this drug class, means it should not be used in people with a personal or family history of medullary thyroid carcinoma or with MEN 2. It should not be combined with another GLP-1 receptor agonist.
What it competes with
Weight-management drugs are now chosen among injectable semaglutide and tirzepatide, oral semaglutide, and older oral options. Tirzepatide and injectable semaglutide produced larger mean weight losses in their own trials, though they have not been compared head to head with orforglipron.
TirzepatideWeekly GIP/GLP-1 injection; largest mean weight loss among approved drugs.
Semaglutide injectionWeekly GLP-1 injection, with cardiovascular outcome data in people with obesity.
Oral semaglutide for weight managementPeptide tablet with fasting and water rules for each dose.
Phentermine-topiramate, naltrexone-bupropionOlder oral options with smaller average weight loss.
Bottom line for clinicians
For adults who prefer a daily pill to weekly injections, Foundayo gives meaningful, sustained weight loss with the familiar GLP-1 side-effect profile. Expected average loss is smaller than with injectable tirzepatide or semaglutide. Screen for medullary thyroid cancer history before starting.
Dosing, contraindications and full warnings are in the prescribing information.
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Last updated October 27, 2026 by 2 Minute Medicine.
For healthcare professionals. A summary of public FDA documents and published trials, not medical advice. Check the full prescribing information before prescribing.
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