Lilly's orforglipron posts about 12.4% weight loss in phase 3

Eli Lilly reported in 2025 that its experimental daily pill orforglipron produced an average weight loss of about 12.4% — roughly 27.3 pounds — at the highest dose after 72 weeks in the phase 3 ATTAIN-1 trial ^[3]. The full results were presented at the European Association for the Study of Diabetes annual meeting and published in The New England Journal of Medicine on September 16, 2025 ^[3]. That data package supported the filing that led to FDA approval on April 1, 2026 under the brand name Foundayo ^[2].

What the trial measured

ATTAIN-1 randomized 3,127 adults with obesity, or overweight plus a weight-related condition such as high blood pressure, abnormal cholesterol, obstructive sleep apnea or cardiovascular disease, and without diabetes ^[3]. Participants took orforglipron at 6 mg, 12 mg or 36 mg daily, or placebo, for 72 weeks, starting at 1 mg and stepping up every four weeks ^[3]. Average starting weight was 103.2 kg (227.5 lbs) with an average BMI of 37.0 ^[3].

All three doses beat placebo ^[3]. Using the "efficacy estimand" — an analysis that estimates results as if everyone had stayed on the drug — average weight change was −7.8% at 6 mg, −9.3% at 12 mg and −12.4% at 36 mg, versus −0.9% for placebo ^[3]. Under the more conservative treatment-regimen estimand, which counts people regardless of whether they stuck with treatment, the 36 mg result was −11.2% versus −2.1% for placebo ^[3]. That is why some summaries describe the pill's effect as "up to about 11%" rather than 12.4% ^[2]; both figures come from the same trial, measured different ways ^[2][3].

At the 36 mg dose, 59.6% of participants lost at least 10% of their body weight, 39.6% lost at least 15%, and 20.1% lost at least 20% ^[3]. Among 1,127 participants who had prediabetes at the start, up to 91% of those on orforglipron reached near-normal blood sugar, compared with 42% on placebo ^[3]. The highest dose also lowered non-HDL cholesterol by 8.5%, triglycerides by 21.6%, systolic blood pressure by 6.7 mm Hg, and the inflammation marker hsCRP by 47.7% in an exploratory analysis ^[3].

Side effects were mostly digestive and mild to moderate ^[3]. At 36 mg, nausea occurred in 33.7% (vs 10.4% on placebo), constipation 25.4% (9.3%), diarrhea 23.1% (9.6%) and vomiting 24.0% (3.5%) ^[3]. Discontinuation because of side effects was 10.3% at 36 mg versus 2.7% on placebo ^[3]. Lilly said no liver safety signal was seen ^[3].

Why it matters for patients

Orforglipron is a small molecule rather than a peptide, so it survives digestion and can be taken any time of day, with or without food or water ^[3]. That distinguishes it from oral semaglutide, which must be swallowed on an empty stomach with a small amount of water, followed by a 30-minute wait before eating, drinking or taking other pills ^[2].

The trade-off is size of effect. One consumer guide puts orforglipron's roughly 12.4% below injectable semaglutide (about 14.9%), tirzepatide (about 20.9%) and the semaglutide pill (about 15–17%) ^[1]. Those are cross-trial comparisons, not head-to-head results, so they should be read with caution. Unlike injectable semaglutide, which has cardiovascular outcome data from the SELECT trial, orforglipron's heart benefit has not been tested ^[1].

Sources also differ on price. One guide lists Foundayo at $149–$349 per month ^[1], while telehealth provider Ro lists $149–$299 per month self-pay depending on dose, and $25–$349 with insurance depending on plan and savings-card eligibility ^[2]. Sources also describe doses differently: the trial and one guide reference a 36 mg maintenance dose ^[1][3], while Ro lists six approved tablet strengths of 0.8, 2.5, 5.5, 9, 14.5 and 17.2 mg ^[2]. The reason for that difference is not explained in these sources.

What happens next

Lilly said in September 2025 that it anticipated submitting orforglipron for type 2 diabetes in 2026 ^[3]; it is not approved for diabetes as of the most recent source ^[2]. One guide reports Foundayo is expected under Medicare Part D from July 2026 at about $50 per month, though that is described as an expectation rather than a confirmed policy ^[1].