Compound Names

What Is Orforglipron?

Published May 2, 2026 · Updated Sep 12, 2026 · 7 minute read

Orforglipron is a once-daily GLP-1 receptor agonist that is not a peptide. That one fact explains most of what is different about it: no injection, no fasting rule, a drug-interaction section peptides do not have, and a phase 3 program that put it against oral semaglutide directly. Lilly sells it as Foundayo.

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Key Takeaways

  • Orforglipron is a conventional small molecule of about 900 daltons, not a peptide, so the gut does not digest it. Oral bioavailability is 77% and food does not change dosing.
  • In ATTAIN-1, the top dose produced 11.2% mean weight loss over 72 weeks against 2.1% on placebo, in 3,127 adults with obesity. In ATTAIN-2, with type 2 diabetes, 9.6% versus 2.5%.
  • Head-to-head with oral semaglutide in ACHIEVE-3, orforglipron lowered HbA1c and weight more, with more gastrointestinal events and discontinuations.
  • The trial papers report 6, 12, and 36 mg arms; the marketed Foundayo tablets are 5.5, 9, and 17.2 mg, a different formulation labelled by a different convention for the same arms.
  • Orforglipron is metabolised by CYP3A4, so strong inhibitors cap the dose at 9 mg. That interaction does not exist for peptide GLP-1 drugs.
Orforglipron
Class GLP-1 receptor agonist, non-peptide small molecule
Size About 900 daltons (semaglutide is about 4,100)
Route Oral, once daily, with or without food
Oral bioavailability 77% (label); oral semaglutide 0.4% to 1%
Steady state After about 1 week
Metabolism CYP3A4; strong inhibitors cap the dose at 9 mg
Trial doses 6, 12, 36 mg, reported as 5.5, 9, 17.2 mg in later analyses
Brand Foundayo, approved April 1, 2026 for weight reduction in adults
Maker Eli Lilly (originally from Chugai)

1. Why a Small Molecule Changes the Rules

Every GLP-1 drug before orforglipron was a peptide: a chain of amino acids that stomach acid and gut enzymes break down. That is why semaglutide, tirzepatide, and liraglutide are injected, and why the semaglutide tablet (Rybelsus) needs 300 mg of an absorption enhancer, an empty stomach, a 4 oz water limit, and a 30-minute wait to get 0.4% to 1% of the dose into the blood.

Orforglipron is a conventional drug molecule that binds the same receptor. It survives digestion on its own, so the label reports 77% absolute bioavailability, a peak 4 to 8 hours after the dose, and steady state after about a week of daily dosing. With food, exposure fell 19% in the label’s study and about 18% to 24% in the published food-effect trial, which the label calls not clinically relevant. The instruction is one line: once daily, with or without food, swallow whole.

The trade-off is metabolism. Peptides are cleared by proteolysis and barely interact with other drugs. Orforglipron is metabolised by CYP3A4, so the label caps the dose at 9 mg with strong CYP3A4 inhibitors, says to avoid strong inducers, and limits simvastatin to 20 mg a day. It also delays gastric emptying like every GLP-1 agonist, with the usual caution about oral medicines with a narrow therapeutic index.

2. Weight Loss: ATTAIN-1 and ATTAIN-2

11.2%mean weight loss on the top dose at 72 weeks in ATTAIN-1, against 2.1% on placebo, in 3,127 adults with obesity and no diabetes. The lower doses produced 7.5% and 8.4%.
9.6%on the top dose in ATTAIN-2, 1,613 adults with obesity and type 2 diabetes, against 2.5% on placebo. Lower doses 5.1% and 7.0%.
5.3% to 10.3%discontinued for adverse events in ATTAIN-1 across the three doses, versus 2.7% on placebo. Gastrointestinal events were the most common.

For scale, semaglutide 2.4 mg produced 14.9% in STEP 1 and tirzepatide 15 mg 20.9% in SURMOUNT-1, both injected and both in separate trials. An oral semaglutide 25 mg tablet produced 13.6% in OASIS 4. Orforglipron sits below those on weight, and the trade is the tablet with no rules.

3. Blood Sugar: ACHIEVE-1 and ACHIEVE-3

ACHIEVE-1 was monotherapy in 559 adults with early type 2 diabetes: from a baseline HbA1c of 8.0%, the three doses lowered it by 1.24, 1.47, and 1.48 percentage points over 40 weeks against 0.41 on placebo, with weight loss of 4.5%, 5.8%, and 7.6% against 1.7%.

ACHIEVE-3 is the trial that matters most for the oral question, because it compared the two oral GLP-1 agonists directly in 1,698 adults with type 2 diabetes over 52 weeks.

Orforglipron 12 mg Orforglipron 36 mg Oral semaglutide 7 mg Oral semaglutide 14 mg
HbA1c change from 8.3% −1.71 pp −1.91 pp −1.23 pp −1.47 pp
Weight change −6.7% −9.2% −3.7% −5.3%
Gastrointestinal events 59% 58% 37% 45%
Discontinued for adverse events 9% 10% 4% 5%
Pulse rate change +3.7 bpm +4.7 bpm +1.0 bpm +1.5 bpm

Orforglipron won on both endpoints and paid for it in tolerability. The Foundayo vs Rybelsus page has the charts and the caveats, including that ACHIEVE-3 is a diabetes trial and Foundayo is not approved for diabetes.

4. Trial Doses and Tablet Strengths

The phase 3 papers report arms of 6, 12, and 36 mg. The Foundayo label lists tablets of 0.8, 2.5, 5.5, 9, 14.5, and 17.2 mg, with 17.2 mg the maximum. The two sets describe the same treatment: the commercial tablet is a different formulation labelled by a different dose convention, and Lilly’s later analyses report the ATTAIN arms as 5.5, 9, and 17.2 mg. The label itself notes that most of its pharmacokinetic data were generated with the investigational formulation. When reading a paper against the box, 6 mg corresponds to 5.5 mg, 12 to 9, and 36 to 17.2.

5. Where the Brand Page Takes Over

The molecule is the same whatever it is called; the label is Foundayo’s. The Foundayo page covers what was approved, the 30-day dose ladder, the missed-dose rule, the CYP3A4 dosage modification, and the safety sections including how the class boxed warning is worded for a drug that is not active in rodents. For the route question in general, see oral vs injectable GLP-1. For the log, a daily tablet is the simplest entry there is: product, date, milligrams.

6. Orforglipron FAQ

  • Is orforglipron a peptide?

    No. Semaglutide, tirzepatide, and liraglutide are peptides, chains of amino acids that the gut breaks down, which is why they are injected or need an absorption enhancer as a tablet. Orforglipron is a conventional small-molecule drug of about 900 daltons that binds the GLP-1 receptor and survives digestion on its own.

  • How much weight loss does orforglipron produce?

    In ATTAIN-1, adults with obesity and no diabetes lost 7.5%, 8.4%, and 11.2% of body weight on the three doses over 72 weeks, against 2.1% on placebo. In ATTAIN-2, adults with obesity and type 2 diabetes lost 5.1%, 7.0%, and 9.6% against 2.5%.

  • Is orforglipron better than oral semaglutide?

    In ACHIEVE-3, the only direct trial, orforglipron 12 and 36 mg lowered HbA1c by 1.71 and 1.91 percentage points over 52 weeks against 1.23 and 1.47 for semaglutide 7 and 14 mg, with weight loss of 6.7% and 9.2% versus 3.7% and 5.3%. Gastrointestinal events were 58% to 59% versus 37% to 45%, and discontinuations for adverse events 9% to 10% versus 4% to 5%. The Foundayo vs Rybelsus page has the detail.

  • Why do the trial doses and the tablet strengths not match?

    The phase 3 papers report 6, 12, and 36 mg arms. The marketed tablets are 5.5, 9, and 17.2 mg. The commercial tablet is a different formulation labelled by a different dose convention, and Lilly's later analyses report the same trial arms under the marketed numbers. The dose steps in the label are 0.8, 2.5, 5.5, 9, 14.5, and 17.2 mg.

  • What is the difference between orforglipron and Foundayo?

    Orforglipron is the molecule; Foundayo is Lilly's brand of it, approved on April 1, 2026 for weight reduction in adults. The Foundayo page covers the label: dosing, missed doses, interactions, and safety.

7. Sources

References used for this article

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