Danuglipron

Danuglipron is an oral, non-peptide small-molecule GLP-1 receptor agonist developed by Pfizer. It was one of the more advanced entries in the oral small-molecule GLP-1 race, but its development was discontinued after a hepatotoxicity (liver-injury) signal — a class-relevant safety concern that also halted other oral small-molecule GLP-1 candidates. It was never approved, and there is no active development program. This page exists to document that history accurately.

What is Danuglipron and what happened to it?

Danuglipron was an oral GLP-1 receptor agonist intended to bring incretin therapy into pill form, but Pfizer ended the program in two steps. In December 2023 it dropped the twice-daily formulation after Phase 2b obesity results: placebo-adjusted weight reductions of −8% to −13% at 32 weeks (−5% to −9.5% at 26 weeks), but with nausea in up to 73%, vomiting in up to 47%, and discontinuation rates above 50% (vs approximately 40% on placebo). Then on April 14, 2025 it discontinued danuglipron entirely after a single asymptomatic participant in a dose-optimization study experienced potential drug-induced liver injury, which resolved after stopping the drug; Pfizer stated that liver-enzyme elevations across its more than 1,400-participant safety database were in line with approved agents in the class, and that the decision followed "a review of the totality of information… and recent input from regulators.". To be plain: danuglipron is not a peptide at all — it is a synthetic small-molecule GLP-1 receptor agonist (PF-06882961) from Pfizer's medicinal-chemistry program, listed on peptide-vendor menus only by association with the GLP-1 class. It is a cautionary example in the oral small-molecule GLP-1 field, contrasting with orforglipron, which advanced without the same liver signal and reached FDA approval in April 2026.

Sources: Pfizer Announces Topline Phase 2b Results of Oral GLP-1R Agonist, Danuglipron, in Adults with Obesity, Pfizer Inc., via pfizer.com (company press release); Pfizer Provides Update on Oral GLP-1 Receptor Agonist Danuglipron (development discontinued), Pfizer Inc., via pfizer.com (company press release); A Small-Molecule Oral Agonist of the Human Glucagon-like Peptide-1 Receptor, Griffith D.A. et al. (Pfizer) — optional, non-blocking follow-up: confirm full author list, J Med Chem, 2022

What does the clinical evidence show?

The human data are real and published: a Phase 1 multiple-ascending-dose trial in type 2 diabetes (Nat Med 2021) showed glucose-lowering and weight effects consistent with the GLP-1 class, and the twice-daily Phase 2b obesity trial has since been published in full (Diabetes Obes Metab 2025). Efficacy was never the program's core problem — Pfizer reported placebo-adjusted weight loss of up to ~13% at 32 weeks with the twice-daily form — tolerability was (GI adverse events and >50% discontinuation), and the final April 2025 discontinuation followed a single potential drug-induced liver-injury case weighed with the totality of program data and regulator input. — so there is no path to approval and no mature outcomes data.

Sources: Danuglipron (PF-06882961) in type 2 diabetes: a randomized, placebo-controlled, multiple ascending-dose phase 1 trial, Saxena A.R., Gorman D.N., Esquejo R.M., Bergman A., et al., Nature Medicine, 2021; Efficacy and safety of danuglipron (PF-06882961) in adults with obesity: A randomized, placebo-controlled, dose-ranging phase 2b study, Buckeridge C. et al. (optional, non-blocking: complete list), Diabetes Obes Metab, 2025; Pfizer Announces Topline Phase 2b Results of Oral GLP-1R Agonist, Danuglipron, in Adults with Obesity, Pfizer Inc., via pfizer.com (company press release); Pfizer Provides Update on Oral GLP-1 Receptor Agonist Danuglipron (development discontinued), Pfizer Inc., via pfizer.com (company press release) · Evidence level: discontinued in development; safety-limited

How does danuglipron compare with the approved incretin drugs?

Danuglipron's efficacy was competitive on paper — its tolerability and a liver-safety question ended it, while every comparator below reached or kept approval. The oral small-molecule niche it targeted was filled by orforglipron (approved April 2026). Figures are each program's own published or company-reported result, not head-to-head.

Evidence level: discontinued Phase 2b (danuglipron); FDA-approved or Phase 3 (comparators)

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What are the known side effects and safety concerns?

Beyond the expected GLP-1-class gastrointestinal effects, the defining concern is drug-induced liver injury — the reason development was halted. Anyone encountering research-market danuglipron should weigh that documented liver-safety signal heavily.

Evidence level: discontinued program

What is the regulatory status, and why is verification (and caution) critical here?

Danuglipron is not approved and is no longer in development — so any "danuglipron" sold through research-chemical vendors is an unapproved, safety-flagged compound of entirely unverified identity. Any vial or capsule sold as "danuglipron" on the research market is a red flag by definition: a discontinued pharmaceutical small molecule with an unresolved liver-safety question, no approved product anywhere, no legitimate bulk supply chain, and no independent lab tests on file at Peptigrity (verified August 2026). A discontinued pharma compound in the research-chemical channel is exactly where substitution and mislabeling thrive — see the grey-market peptides guide. For how oral small-molecule GLP-1s differ from injectable peptides, see oral GLP-1s vs peptides. Both the counterfeit risk and the known liver signal argue for extreme caution. See the legal status guide.

How does Peptigrity verify Danuglipron?

Peptigrity collects independent third-party Certificates of Analysis for danuglipron from shops' official channels and verifies each for authenticity before publishing — as of August 2026 none are on file, which is itself the signal: nobody is independently verifying this compound. Because shops choose which COAs to publish, results reflect the batches shops have made public rather than every production batch — a selection bias we state openly. A community-funded Testing Grant to purchase and test vials anonymously is in development. Tests in the database come from independent labs such as Janoshik Analytical, Freedom Diagnostics, and Chromate. The trust score weights lab purity and reviews equally (50/50). Any future results appear at the independent danuglipron lab tests page. See how to read lab results.

This section is for educational and informational purposes only and does not constitute medical advice. Danuglipron is not approved by the FDA or equivalent regulators for human use; its development was discontinued in April 2025. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.

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