Compound Profile — Last checked October 12, 2026

Foundayo (Orforglipron) — Oral Non-Peptide GLP-1 Profile

Orforglipron (brand name Foundayo) is Eli Lilly’s once-daily oral small-molecule GLP-1 receptor agonist, FDA approved on April 1, 2026 for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. The first non-peptide oral GLP-1 agonist, free of the food-and-timing restrictions that constrain Rybelsus. In ATTAIN-1 the top dose (36 mg in the trial, marketed as Foundayo 17.2 mg) cut body weight by 12.4% at 72 weeks on the efficacy estimand and 11.2% on the primary treatment-regimen estimand.

·
Fact-checked · Reviewed by Remy Research Editorial Board
Update History ▾
October 12, 2026: Corrected ATTAIN-1 — the trial never reported 14.3%; its top dose (36 mg in the trial, which the FDA label presents as Foundayo 17.2 mg) gave 12.4% on the efficacy estimand and 11.2% on the primary treatment-regimen estimand (vs 0.9% and 2.1% placebo), and the trial doses were 6, 12 and 36 mg. This supersedes the May 17, 2026 note, which treated the 36 mg arm and the 17.2 mg label dose as different groups. Removed the “first oral GLP-1 with injectable-class efficacy” claims (the Wegovy pill was approved first), updated the retatrutide comparator to TRIUMPH-1 (NEJM, September 2026), corrected the adverse-event discontinuation line, added the UAE (EDE, announced April 3, 2026) and Saudi (SFDA, August 2, 2026) approvals, and corrected the Phase 2 and ATTAIN-MAINTAIN references; added the ATTAIN-1, OASIS 4 and ACHIEVE-4 papers. Corrected the May 12, 2026 maintenance callout: ATTAIN-MAINTAIN tested Foundayo alone after Wegovy or Zepbound (0.9 kg and 5.0 kg regain), and the separate SURMOUNT-MAINTAIN trial tested stepping Zepbound down to 5 mg (5.6 kg). Put the brand name Foundayo in the opening sentence and added a brand-name FAQ, checked against Drugs@FDA (NDA 220934) and the current FOUNDAYO label.
October 7, 2026: Freshness update — recorded the U.S. type 2 diabetes submission (Lilly Q2 2026 report), UK MHRA authorisation (August 10, 2026, weight management and type 2 diabetes) and detailed ACHIEVE-4 cardiovascular results (September 30, 2026).
July 15, 2026: Citation hygiene — replaced bare-homepage citation links with exact primary-source deep links (specific press releases, ClinicalTrials.gov records, and dated news articles). Anchor text and article copy unchanged.
June 4, 2026: Added ATTAIN-MAINTAIN (NCT06584916) to the Phase 3 programme table and cited the ClinicalTrials.gov registry record for the Phase 3b maintenance trial alongside the existing Nature Medicine readout.
May 23, 2026: Added Lilly ATTAIN-MAINTAIN press readout (May 12, 2026) on Foundayo and lower-dose Zepbound holding weight loss after switch from max-tolerated Wegovy with modest regain (~0.9–5 kg by cohort); added ATTAIN-1/-2 post-hoc geriatric data (adults ≥65, May 2026); added ACHIEVE-4 sustained T2D + weight benefit at extended follow-up.
May 18, 2026: Added second May 2026 research update on ATTAIN-MAINTAIN Phase 3b (Aronne et al, Nat Med, PMID 42120723) — first Phase 3 data on orforglipron preserving weight loss after stopping injectable tirzepatide or semaglutide.
May 18, 2026: Added May 2026 research update on the Zaman & Amin Expert Opinion on Pharmacotherapy positioning review (PMID 42138103), which frames orforglipron as a route-preference option rather than an efficacy leader and flags four gating uncertainties: durability, persistence, affordability, and real-world safety.
May 17, 2026: Corrected Foundayo indication — FDA approval (April 1, 2026) is for chronic weight management, not type 2 diabetes; ACHIEVE supports the separate T2D filing path. Added approved-label dose context (17.2 mg cap, ~12.4% at 72 weeks) alongside the 36 mg ATTAIN-1 trial data. Refreshed retatrutide comparator to Phase 3 TRIUMPH-4 (28.7%).
April 22, 2026: Initial publication of dedicated compound profile
TL;DR — What Is Orforglipron?

Orforglipron (LY3502970) is Eli Lilly’s once-daily oral non-peptide GLP-1 receptor agonist, FDA approved under the brand name Foundayo on April 1, 2026 for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. Unlike Rybelsus (an oral formulation of the peptide semaglutide), orforglipron is a small molecule that is metabolically stable in the gastrointestinal tract and has no food or timing restrictions. In ATTAIN-1, the top dose (36 mg in the trial; marketed as Foundayo 17.2 mg) produced 12.4% weight loss at 72 weeks on the efficacy estimand (11.2% on the primary treatment-regimen estimand) — somewhat less than injectable semaglutide 2.4 mg, with no food or water timing rules. The Wegovy pill (oral semaglutide 25 mg, FDA-approved December 22, 2025) was the first oral GLP-1 approved for weight management.

Key Takeaways

What Is Orforglipron?

Orforglipron (development code LY3502970) is Eli Lilly’s once-daily oral GLP-1 receptor agonist. The critical structural distinction: it is a small-molecule non-peptide. Every other clinically meaningful GLP-1 agonist — semaglutide, liraglutide, dulaglutide, tirzepatide, retatrutide — is a peptide or engineered peptide variant. Peptides are not natively stable in the gastric environment, which is why they are either injected or paired with absorption enhancers (as in Rybelsus).

Because orforglipron is a small molecule, it survives the GI tract intact and absorbs reliably without food or timing restrictions. This is the single most consequential pharmacokinetic difference in the oral GLP-1 space. Orforglipron received FDA approval under the brand name Foundayo on April 1, 2026 for chronic weight management. For the full approval timeline and current regulatory status, see Is orforglipron approved?

Mechanism of Action

Orforglipron binds the GLP-1 receptor at an allosteric site distinct from the orthosteric pocket where native GLP-1 and peptide analogs like semaglutide bind. Despite the different binding geometry, orforglipron triggers similar downstream G-protein signalling and produces clinically comparable effects:

The practical implication of non-peptide architecture is pharmacokinetic rather than pharmacodynamic. Orforglipron is absorbed reliably regardless of food intake or timing — a sharp contrast with Rybelsus, which requires dosing on an empty stomach with a small sip of water followed by a 30-minute fast. For patients and laboratories comparing oral options, this is the decisive differentiator. See oral obesity drugs in 2026 for class context.

Phase 3 Programmes — ACHIEVE & ATTAIN

Orforglipron’s Phase 3 dataset is organised into two programmes: ATTAIN for obesity (supporting the approved Foundayo label) and ACHIEVE for type 2 diabetes (supporting the separate type 2 diabetes submission). Eli Lilly tested 6, 12 and 36 mg once-daily doses in ATTAIN and 3, 12 and 36 mg in ACHIEVE-1, using an investigational capsule; the U.S. label presents the ATTAIN doses as the equivalent Foundayo tablet doses of 5.5, 9 and 17.2 mg.

Orforglipron Phase 3 Programme Overview
Programme Focus Headline readout
ACHIEVE-1 Type 2 diabetes monotherapy HbA1c reduction ~1.3–1.6%
ACHIEVE-2–5 T2D add-on / special populations Consistent glycemic & weight effect
ATTAIN-1 Obesity without T2D, 72 wk 12.4% (efficacy) / 11.2% (treatment-regimen) at the top dose (36 mg = Foundayo 17.2 mg)
ATTAIN-2 Obesity + T2D Reported 2025
ATTAIN-MAINTAIN Weight-loss maintenance after injectable GLP-1/GIP switch (Phase 3b) Held 74.7% (post-tirzepatide) and 79.3% (post-semaglutide) of weight loss at 52 wk

Regulatory status: Foundayo (orforglipron for chronic weight management) was FDA approved on April 1, 2026 under the Commissioner’s National Priority Voucher pilot programme. Lilly reported the separate U.S. type 2 diabetes submission, supported by the ACHIEVE programme, in its Q2 2026 results (August 5, 2026). Outside the U.S., the UAE’s Emirates Drug Establishment announced its approval of Foundayo on April 3, 2026, the second country worldwide (patient availability from May 2026); Saudi Arabia’s SFDA approved its registration on August 2, 2026; and the UK MHRA authorised orforglipron on August 10, 2026 for weight management and type 2 diabetes. No EU approval had been announced when we checked on October 12, 2026. For a running regulatory view, see the Foundayo FDA approval tracker.

Efficacy Data — ATTAIN-1

ATTAIN-1 was a 72-week, randomised, double-blind, placebo-controlled Phase 3 trial in 3,127 adults with obesity without type 2 diabetes (Wharton et al., N Engl J Med 2025). The top dose — 36 mg in the trial’s capsule formulation, which the FDA label presents as Foundayo 17.2 mg — reduced body weight by 12.4% at 72 weeks on the efficacy estimand and 11.2% on the primary treatment-regimen estimand, versus 0.9% and 2.1% with placebo. The 6 mg and 12 mg arms (Foundayo 5.5 mg and 9 mg) gave 7.8% and 9.3% on the efficacy estimand, or 7.5% and 8.4% on the treatment-regimen estimand — a clean dose-response.

Two framing points matter for positioning:

The glycemic data from ACHIEVE-1 (HbA1c reductions in the 1.3–1.6% range) is competitive with injectable semaglutide in diabetes populations, which supports the type 2 diabetes submission (the U.S. Foundayo label currently covers weight management only; the UK authorisation includes type 2 diabetes). For a focused oral-class comparison, see oral obesity drugs 2026. For a head-to-head framing, see retatrutide vs orforglipron.

May 2026 Research Update — ATTAIN-MAINTAIN Phase 3b

A Phase 3b maintenance trial in Nature Medicine (Aronne et al, May 12, 2026) tested whether orforglipron could preserve weight loss in 376 adults who had already lost weight on injectable GLP-1s. Over 52 weeks, orforglipron maintained 74.7% of weight loss in patients previously on tirzepatide (vs 49.2% on placebo; Δ 25.5%, 95% CI 14.5–36.5; P<0.001) and 79.3% in patients previously on semaglutide (vs 37.6%; Δ 41.7%, 95% CI 24.4–59.0; P<0.001). Adverse events were predominantly mild-to-moderate GI. This is the first Phase 3 evidence that an oral GLP-1 can hold the line on weight loss achieved by injectable incretins.

May 12, 2026 Update — Foundayo and Lower-Dose Zepbound Maintenance Readouts

Lilly’s May 12, 2026 press readout covered two late-phase trials. In ATTAIN-MAINTAIN, participants who switched from the maximum tolerated dose of Wegovy or Zepbound to Foundayo (orforglipron) alone kept all but 0.9 kg (after Wegovy) and 5.0 kg (after Zepbound) of their prior weight loss after a year. In the separate SURMOUNT-MAINTAIN trial, stepping Zepbound (tirzepatide) down to 5 mg kept all but 5.6 kg. The result repositions Foundayo as a viable oral maintenance step-down option after injectable GLP-1 induction and reshapes the maintenance-dosing narrative for the wider GLP-1 class.

May 2026 Update — ATTAIN-1/-2 Post-Hoc in Older Adults (≥65)

A post-hoc analysis of ATTAIN-1 and ATTAIN-2 showed adults aged 65 and older achieved weight loss comparable to younger participants on Foundayo, supporting use in older populations and broadening the relevant age band beyond the headline pivotal cohort.

April 2026 Update — ACHIEVE-4 Sustained T2D + Weight Benefit

ACHIEVE-4 reported sustained glycemic control and weight benefit on orforglipron at extended follow-up in adults with type 2 diabetes, supporting the diabetes indication. Lilly has since reported the U.S. type 2 diabetes submission (Q2 2026 results, August 5, 2026); the U.S. Foundayo label is still obesity-only while that review runs.

Safety & Tolerability

Orforglipron’s safety profile is consistent with the GLP-1 class:

Because orforglipron is oral and small-molecule, there is no injection-site reaction class typical of subcutaneous peptide drugs. This simplifies long-term adherence.

How It Compares — Orforglipron vs Class

Orforglipron’s strategic position is defined by oral convenience traded against somewhat lower efficacy than the injectable incretins:

The clinical and commercial question orforglipron answers is: how much oral convenience is worth, relative to roughly 10–14 percentage points more weight loss from an injectable dual or triple agonist? For patients resistant to injectables, orforglipron is likely the preferred first-line agent. For patients seeking maximum weight loss, it is not competitive with tirzepatide or retatrutide.

May 2026 Research Update — Clinical-Position Review

A narrative review in Expert Opinion on Pharmacotherapy (Zaman & Amin, May 15, 2026) frames orforglipron as a meaningful expansion of obesity pharmacotherapy for patients who prefer oral routes, but cautions that comparative efficacy may not exceed leading injectable incretins. The authors flag four uncertainties as the gating issues: long-term durability, persistence on therapy, affordability, and real-world safety. The review positions orforglipron as a route-preference option rather than an efficacy leader, with clinical value depending on tolerability, access, and individualised goals rather than headline weight loss alone.

Research Use Notes

Orforglipron as a finished drug product is proprietary to Eli Lilly and is not supplied as a research-grade reference standard through mainstream channels. Laboratories characterising oral GLP-1 receptor pharmacology typically rely on the published ACHIEVE and ATTAIN clinical pharmacology disclosures and class-adjacent oral GLP-1 research compounds.

Remy Research supplies retatrutide pens and vials as its anchor next-generation obesity reference compound. Janoshik HPLC reports are published for selected batches — for example the Remedium Research 30mg FlexiPen (Janoshik Analytical Batch RETP002, 99.262% purity) — and each product page shows its own testing status. Retatrutide is the unimolecular triple agonist at the mechanistic ceiling of the obesity pipeline — the logical reference for laboratories comparing novel oral and injectable GLP-1-class mechanisms. See the Dubai research guide for full laboratory context.

All Remy Research products are supplied for in-vitro laboratory research only. Not for human or veterinary use.

Frequently Asked Questions
Orforglipron (LY3502970) is Eli Lilly’s once-daily oral non-peptide GLP-1 receptor agonist. Unlike semaglutide or tirzepatide, which are peptide drugs requiring injection or special absorption chemistry, orforglipron is a small-molecule GLP-1 agonist that can be taken as a conventional oral tablet without food or timing restrictions. It received FDA approval under the brand name Foundayo for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity.
Foundayo. The FDA approved Eli Lilly’s Foundayo (orforglipron) tablets on April 1, 2026 (NDA 220934). The label indication is to reduce excess body weight and maintain weight reduction long term, together with a reduced-calorie diet and increased physical activity. It covers adults with obesity, and adults with overweight and at least one weight-related comorbid condition. Orforglipron is the generic name, and LY3502970 is its development code. The U.S. label covers weight management only; Lilly’s type 2 diabetes application is still under FDA review.
Yes. Orforglipron received FDA approval under the brand name Foundayo on April 1, 2026 for chronic weight management. It is the first non-peptide oral GLP-1 receptor agonist to reach market. Lilly has submitted orforglipron for type 2 diabetes in the U.S. (Q2 2026 report); the approved U.S. Foundayo label is for weight management. Outside the U.S., the UAE’s Emirates Drug Establishment announced its approval on April 3, 2026 (the second country worldwide), Saudi Arabia’s SFDA approved its registration on August 2, 2026, and the UK MHRA authorised it on August 10, 2026 for weight management and type 2 diabetes. For the latest regulatory status, see our approval tracker.
In ATTAIN-1, the pivotal Phase 3 obesity trial, the top dose (36 mg in the trial, marketed as Foundayo 17.2 mg) produced 12.4% mean weight loss at 72 weeks versus 0.9% on placebo on the efficacy estimand, or 11.2% versus 2.1% on the primary treatment-regimen estimand (N Engl J Med 2025). That is somewhat less than injectable semaglutide 2.4 mg in STEP 1 (14.9% at 68 weeks); orforglipron’s advantage is that it has no food or water timing rules.
Orforglipron is a small-molecule GLP-1 receptor agonist. It binds the GLP-1 receptor at an allosteric site distinct from where native GLP-1 or peptide analogs like semaglutide bind, but it triggers similar downstream G-protein signalling. The clinical effects — appetite suppression, slowed gastric emptying, enhanced glucose-dependent insulin secretion — mirror injectable GLP-1 agonists. The critical pharmacokinetic difference is that orforglipron is stable in the gastrointestinal tract and absorbed reliably without food or timing restrictions.
Rybelsus is an oral formulation of the peptide semaglutide, paired with the absorption enhancer SNAC. Peptide stability in the gastric environment is inherently unreliable, so Rybelsus must be taken on an empty stomach with a small sip of water and a 30-minute fast afterward. Orforglipron is a small molecule, not a peptide, so it is metabolically stable in the gut and has no food or timing restrictions. This is a practical convenience advantage that may broaden GLP-1 class adoption.
Comparing regardless-of-adherence results, orforglipron (11.2% in ATTAIN-1) is below injectable semaglutide 2.4 mg (14.9% in STEP 1), tirzepatide 15 mg (20.9% in SURMOUNT-1) and retatrutide 12 mg (25.0% in Phase 3 TRIUMPH-1, treatment-regimen estimand; 28.3% efficacy estimand). The differentiator is oral convenience. Orforglipron is expected to expand GLP-1 class access for patients who resist injectables, but it does not match the weight-loss ceiling of dual and triple agonists.
Orforglipron as a finished drug product is proprietary to Eli Lilly. Remy Research does not supply orforglipron. For laboratories characterising oral GLP-1 receptor pharmacology, the published ACHIEVE and ATTAIN clinical pharmacology disclosures are the primary reference. Remy Research supplies retatrutide for in-vitro research as its next-generation obesity reference compound; Janoshik HPLC reports are published for selected batches, and each product page shows its own testing status.

Our Research Standards

This article cites peer-reviewed studies, FDA filings, and ClinicalTrials.gov data. All claims are cross-referenced against primary sources. We update articles when new trial data or regulatory decisions are published. Read our editorial policy →

RP
Editorial Review

Editorial Board, Remy Research

The Remy Research Editorial Board reviews research articles covering GLP-1 receptor agonists, triple agonists, and the obesity drug pipeline. Its review spans peptide analytical chemistry, HPLC purity validation, and clinical trial data interpretation.

About the editorial team →
References & Citations
  1. Eli Lilly. FDA approval of Foundayo (orforglipron) for chronic weight management. 2026. investor.lilly.com
  2. Eli Lilly. ACHIEVE Phase 3 programme: Orforglipron in type 2 diabetes. investor.lilly.com
  3. Eli Lilly. ATTAIN-1 Phase 3 obesity trial results. investor.lilly.com
  4. Wharton S, Blevins T, Connery L, et al. Daily Oral GLP-1 Receptor Agonist Orforglipron for Adults with Obesity. N Engl J Med. 2023;389(10):877-888. nejm.org
  5. Frías JP, Hsia S, Eyde S, et al. Efficacy and safety of oral orforglipron in patients with type 2 diabetes: a multicentre, randomised, dose-response, phase 2 study. Lancet. 2023;402(10400):472-483. PMID 37369232. pubmed.ncbi.nlm.nih.gov
  6. ClinicalTrials.gov. ATTAIN-1: A Study of Daily Oral Orforglipron in Adult Participants With Obesity. clinicaltrials.gov
  7. Zaman W, Amin A. Orforglipron and the emergence of oral GLP-1 therapy for obesity: efficacy, safety, and clinical positioning. Expert Opin Pharmacother. 2026 May 15. PMID 42138103. pubmed.ncbi.nlm.nih.gov
  8. Aronne LJ, Horn DB, le Roux CW, et al. Orforglipron for maintenance of body weight reduction: the double-blind, randomized phase 3b ATTAIN-MAINTAIN trial. Nat Med. 2026;32(7):2679–2687. PMID 42120723. pubmed.ncbi.nlm.nih.gov
  9. ClinicalTrials.gov. ATTAIN-MAINTAIN: A Study of Orforglipron for the Maintenance of Body Weight Reduction in Participants Who Have Obesity or Overweight With Weight-Related Comorbidities (NCT06584916). Eli Lilly and Company. Phase 3b. clinicaltrials.gov
  10. Eli Lilly. Foundayo and lower-dose Zepbound helped people maintain weight loss after switching from higher doses of injectable incretin therapy — ATTAIN-MAINTAIN readout. May 12, 2026. prnewswire.com
  11. Orforglipron linked to weight loss in older adults in ATTAIN post-hoc analysis. Patient Care Online. May 2026. patientcareonline.com
  12. Orforglipron demonstrates sustained glycemic control and weight loss in Phase 3 ACHIEVE-4 trial. Pharmacy Times. April 2026. pharmacytimes.com
  13. UK Government (MHRA). UK first in Europe to authorise orforglipron for weight management and type 2 diabetes. August 10, 2026. gov.uk
  14. Eli Lilly. Lilly reports second-quarter 2026 financial results. August 5, 2026. investor.lilly.com
  15. Eli Lilly. Foundayo demonstrated cardiovascular safety alongside sustained A1C reduction and weight loss — ACHIEVE-4 detailed results. September 30, 2026. prnewswire.com
  16. Wharton S, Aronne LJ, Stefanski A, et al. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment (ATTAIN-1). N Engl J Med. 2025;393(18):1796–1806. PMID 40960239. pubmed.ncbi.nlm.nih.gov
  17. Wharton S, Lingvay I, Bogdanski P, et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity (OASIS 4). N Engl J Med. 2025;393(11):1077–1087. PMID 40934115. pubmed.ncbi.nlm.nih.gov
  18. Klein KR, Wysham C, Tuttle KR, et al. Cardiovascular safety of orforglipron versus insulin glargine in adults with type 2 diabetes at increased cardiovascular risk (ACHIEVE-4). Lancet. Published online September 30, 2026. PMID 42815506. pubmed.ncbi.nlm.nih.gov
  19. Emirates Drug Establishment. Emirates Drug Establishment approves oral obesity treatment, marking shift away from injections. April 3, 2026. ede.gov.ae
  20. Saudi Food and Drug Authority. SFDA approves registration of “Foundayo” for weight management. August 2, 2026. sfda.gov.sa
  21. U.S. Food & Drug Administration. FOUNDAYO (orforglipron) tablets, prescribing information, revised 07/2026. accessdata.fda.gov

Related Research

Approval Foundayo — Orforglipron FDA Approval Tracker → Status Is Orforglipron Approved Yet? → Class Oral Obesity Drugs in 2026 → Comparison Retatrutide vs Orforglipron → Compound Brenipatide — Lilly's GIP/GLP-1 Beyond Weight Loss → Compound Retatrutide — Triple Agonist Profile → Compound Semaglutide — GLP-1 Receptor Agonist Profile → Tracker Obesity Drug Approval Tracker 2026 → Product Retatrutide Pen 30mg — UAE Research Supply → Catalog Research Peptide Catalog — Current Formats → Tracker Orforglipron Phase 3 evidence tracker →