Orforglipron vs oral semaglutide
Last updated: October 2, 2026 · 5 min read · By the Grey Peptides Editorial Board
- Orforglipron and oral semaglutide are the two GLP-1 drugs taken as pills, but they are different kinds of molecule: orforglipron is a small, non-peptide chemical, and oral semaglutide is the semaglutide peptide formulated as a tablet.
- In ACHIEVE-3, a 52-week head-to-head trial in type 2 diabetes, orforglipron lowered HbA1c more at both dose pairs (1.71% and 1.91% against 1.23% and 1.47%).
- Orforglipron also caused more gastrointestinal side effects and more people stopped it because of side effects. It was approved in the US on April 1, 2026, as Foundayo.
Side by side
Orforglipron Medium is a small-molecule GLP-1 receptor agonist: a chemical drug, not a peptide, that switches on the same receptor as semaglutide High. Oral semaglutide is the semaglutide peptide itself, made into a tablet that survives the stomach. Our semaglutide entry covers both the injected and the oral forms, so the table compares orforglipron with semaglutide as a whole; each entry's dosage page gives the labelled doses with their sources.
| Field | Orforglipron | Semaglutide |
|---|---|---|
| Encyclopedia entry | Orforglipron Full entry | Semaglutide Full entry |
| Molecule class | Small molecule, not a peptide | Peptide |
| Category | Metabolic | Metabolic |
| FDA status | FDA Approved | FDA Approved |
| Approved elsewhere | None recorded | None recorded |
| Evidence grade | Medium | High |
| Half-life | ≈ 39 hours | ≈ 7 days |
| Formula | C48H48F2N10O5 | C187H291N45O59 |
| Molecular weight | 883.0 g/mol | 4,113.6 g/mol |
| WADA 2026 | Not on the 2026 List | Not on the 2026 List |
| WADA 2027 | Not on the 2027 List | Not on the 2027 List |
| In one line | Not a peptide: an oral small-molecule GLP-1 receptor agonist, FDA-approved on April 1, 2026 as Foundayo for weight management; at its top dose it cut weight 11.2% over 72 weeks in ATTAIN-1, against 2.1% on placebo. | A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management. |
| Mechanism | Non-peptide agonist at the GLP-1 receptor: it binds an upper pocket formed by the extracellular domain, extracellular loop 2 and transmembrane helices 1, 2, 3 and 7, acting as a partial agonist biased to G-protein signalling; its dependence on the primate-specific Trp33 makes it inactive in rats and mice. Effects in people are the class's: lower glucose and body weight with gastrointestinal side effects during dose escalation. | Agonist at the GLP-1 receptor. Enhances glucose-dependent insulin secretion, suppresses inappropriate glucagon, slows gastric emptying, and acts centrally to reduce appetite via hypothalamic and area postrema pathways. Weight loss is driven primarily by the central appetite-suppressing effect rather than the peripheral metabolic actions. |
| Sources in the entry | 16 | 14 |
| Study cards | 14 | 8 |
| Dosage page | None | Dosage page |
Head to head: ACHIEVE-3
ACHIEVE-3 compared the two pills directly for 52 weeks in 1,698 adults with type 2 diabetes not controlled on metformin, in an open-label trial (participants knew which drug they took) 1. It was designed to show that orforglipron was no worse than semaglutide, within a margin of 0.3 percentage points of HbA1c, at two matched dose pairs 1. From a starting HbA1c of 8.3%, average HbA1c fell 1.71% on orforglipron 12 mg and 1.91% on 36 mg, against 1.23% on semaglutide 7 mg and 1.47% on 14 mg 1. The differences, 0.48 percentage points at the lower dose pair and 0.44 at the higher, favoured orforglipron 1.
The trade-off was tolerability. Gastrointestinal side effects, mostly mild to moderate, occurred in 59% and 58% of orforglipron users against 37% and 45% on semaglutide, and 9% and 10% stopped orforglipron because of side effects against 4% and 5% on semaglutide 1. Pulse rate also rose more on orforglipron 1.
Each drug against placebo
Outside the head-to-head trial, orforglipron has its own placebo-controlled results. In ACHIEVE-1, in 559 adults with early type 2 diabetes, HbA1c fell by 1.24, 1.47 and 1.48 points on 3, 12 and 36 mg over 40 weeks against 0.41 on placebo, weight fell 4.5% to 7.6% against 1.7%, and there was no severe hypoglycaemia 2. In ATTAIN-1, in 3,127 adults with obesity and no diabetes, weight fell 7.5%, 8.4% and 11.2% on 6, 12 and 36 mg over 72 weeks against 2.1% on placebo 3. In ATTAIN-2, in 1,613 adults with obesity and type 2 diabetes, weight fell 5.1%, 7.0% and 9.6% against 2.5% 4. Against an established diabetes tablet, dapagliflozin 10 mg, orforglipron lowered HbA1c by 1.23 to 1.56 points over 40 weeks against 0.81 in 962 adults 5, and added to insulin glargine it lowered HbA1c by 1.58 to 1.88 points against 0.79 on placebo 6. A further trial, ATTAIN-MAINTAIN, tested it as a maintenance pill for people who had already lost weight on injected tirzepatide or semaglutide 7. Oral semaglutide's best-known comparison is PIONEER 4, where it matched injected liraglutide on HbA1c (1.2 against 1.1 points over 26 weeks) 8.
How the differences add up
On blood sugar, orforglipron did better than oral semaglutide at the doses compared; on side effects, it did worse. Because the trial was open-label, the side-effect reports could be influenced by participants knowing their treatment, though HbA1c is a laboratory measure and less open to that. The trial abstract does not report a weight comparison, so this page does not make one.
Practical differences matter too. Orforglipron is a chemical drug made without the peptide manufacturing that limits semaglutide supply, and semaglutide has far more years of use and outcome data behind it, including the heart-outcome trials covered on our semaglutide vs liraglutide page. Which suits a particular person is a decision for a prescriber.
Status as of October 2, 2026
Orforglipron was approved by FDA on April 1, 2026, as Foundayo (NDA 220934) 9. Oral semaglutide is FDA-approved and covered in our semaglutide entry; our orforglipron entry covers its trials in full.
Frequently asked questions
Which GLP-1 pill lowers blood sugar more?
In the ACHIEVE-3 head-to-head trial, orforglipron lowered HbA1c by 1.71% to 1.91% over 52 weeks against 1.23% to 1.47% for oral semaglutide.
Which has more side effects?
Orforglipron: gastrointestinal side effects occurred in 58% to 59% of users against 37% to 45% on oral semaglutide, and more people stopped it because of side effects.
Is orforglipron approved?
Yes. FDA approved it on April 1, 2026, as Foundayo.
Related on Grey Peptides
Sources
- Rosenstock, J., Yabe, D., Cox, D., et al. (2026). Efficacy and safety of once-daily oral orforglipron compared with oral semaglutide in adults with type 2 diabetes (ACHIEVE-3): a multinational, multicentre, non-inferiority, open-label, randomised, phase 3 trial. Lancet, 407(10534), 1147-1160. PMID: 41765029
- Rosenstock, J., Hsia, S., Nevarez, R., et al. (2025). Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist, in Early Type 2 Diabetes. N Engl J Med, 393(11), 1065-1076. PMID: 40544435
- Wharton, S., Aronne, L. J., Stefanski, A., et al. (2025). Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment. N Engl J Med, 393(18), 1796-1806. PMID: 40960239
- Horn, D. B., Ryan, D. H., Kis, S. G., et al. (2026). Orforglipron, an oral small-molecule GLP-1 receptor agonist, for the treatment of obesity in people with type 2 diabetes (ATTAIN-2): a phase 3, double-blind, randomised, multicentre, placebo-controlled trial. Lancet, 406(10522), 2927-2944. PMID: 41275875
- Welch, M., Forst, T., Jia, W., et al. (2026). Orforglipron compared with dapagliflozin in adults with type 2 diabetes and inadequate glycaemic control with metformin (ACHIEVE-2): a multicentre, randomised, non-inferiority, open-label, phase 3 trial. Lancet, 408(10550), 125-140. PMID: 42259339
- Giorgino, F., D'Souza, S., Ludwig, L., et al. (2026). Orforglipron Added to Titrated Insulin Glargine in Type 2 Diabetes: The ACHIEVE-5 Randomized Clinical Trial. JAMA, 336(5), 389-399. PMID: 42251769
- Aronne, L. J., Horn, D. B., le, R., et al. (2026). Orforglipron for maintenance of body weight reduction: the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial. Nat Med, 32(7), 2679-2687. PMID: 42120723
- Pratley, R., Amod, A., Hoff, S. T., et al. (2019). Oral semaglutide versus subcutaneous liraglutide and placebo in type 2 diabetes (PIONEER 4): a randomised, double-blind, phase 3a trial. Lancet, 394(10192), 39-50. PMID: 31186120
- US Food and Drug Administration. Drugs@FDA (openFDA): FOUNDAYO (orforglipron), NDA 220934, original approval April 1, 2026; read October 2, 2026.
Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.
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