Orforglipron Phase 2 obesity results show up to 14.7% weight loss at 36 weeks
A once-daily GLP-1 pill showed meaningful weight loss in mid-stage testing; the drug is now FDA-approved as Foundayo for adults with obesity or overweight.
Eli Lilly's orforglipron, an experimental once-daily oral GLP-1 pill, helped adults with obesity or overweight lose up to 14.7% of their body weight at 36 weeks in a Phase 2 trial, with results published in the New England Journal of Medicine on June 23, 2023 [1].
In the study, listed on ClinicalTrials.gov as NCT05051579 [2], participants were assigned to orforglipron or to a placebo. Weight loss on orforglipron ranged from 8.6% to 12.6% at 26 weeks, compared with 2.0% on placebo, and from 9.4% to 14.7% at 36 weeks, compared with 2.3% on placebo [1]. Those ranges reflect the different doses tested; the specific Phase 2 doses are not listed in the approval history [1]. The number of people enrolled in the trial has not been reported.
The trial enrolled adults with obesity or overweight who also had at least one weight-related health condition [1][2].
Orforglipron is a small-molecule, non-peptide GLP-1 receptor agonist [1]. It works by binding to and activating GLP-1 receptors in brain regions that regulate appetite and calorie intake; it reduces body weight with more fat mass lost than lean mass, and lowers food intake by decreasing appetite and delaying gastric emptying [1].
From mid-stage results to an approved pill
On April 1, 2026, the FDA approved orforglipron under the brand name Foundayo for adults with obesity, or adults with overweight who have at least one weight-related condition, for use with a reduced-calorie diet and increased physical activity [1]. It is a once-daily tablet taken with or without food [1].
Approval was supported by the ATTAIN Phase 3 program [1]. In ATTAIN-1, a 72-week trial of 3,127 adults with obesity or overweight who did not have diabetes, people taking the highest dose who stayed on treatment lost an average of 27.3 pounds (12.4%), compared with 2.2 pounds (0.9%) on placebo; counting everyone regardless of whether they completed treatment, the average was 25 pounds (11.1%) versus 5.3 pounds (2.1%) [1].
The Phase 2 and Phase 3 results come from separate trials of different lengths and doses, so the percentages should not be compared directly.
Why it matters for patients
For people who prefer not to inject a GLP-1 medicine, orforglipron adds an oral option. Foundayo tablets are taken once daily with or without food, according to the prescribing information summarized in the approval history [1].
Foundayo carries a boxed warning for the risk of thyroid C-cell tumors. Its listed warnings also include acute pancreatitis, severe gastrointestinal reactions, acute kidney injury from volume depletion, low blood sugar, serious allergic reactions, diabetic retinopathy complications in people with type 2 diabetes, acute gallbladder disease, and pulmonary aspiration during general anesthesia or deep sedation [1].
Common side effects, reported in at least 5% of patients, include nausea, constipation, diarrhea, vomiting, indigestion, abdominal pain, headache, abdominal bloating, fatigue, belching, acid reflux, gas, and hair loss [1].
How orforglipron compares with injectable semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro, Zepbound) for weight loss has not been reported. A head-to-head trial compared orforglipron with oral semaglutide in people with type 2 diabetes, not in obesity [1].
What happens next
Foundayo was approved on April 1, 2026 [1]. The approval history lists orforglipron as also being studied for type 2 diabetes, obstructive sleep apnea, and high blood pressure in adults with obesity [1].
Pricing and insurance coverage for Foundayo have not been reported.
Sources
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