For laboratory research use only. Not for human consumption. Not evaluated by the FDA.

What Is Retatrutide?

Retatrutide is a synthetic peptide and first-in-class triple receptor agonist that simultaneously targets glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and glucagon receptors. It is the first "triagonist" in its class and is currently the subject of Phase 3 clinical trials (SURMOUNT program) by Eli Lilly, making it one of the most actively researched metabolic peptides in existence.

Chemical Identity

• Also known as: LY3437943
• Classification: Triple GLP-1/GIP/Glucagon receptor agonist
• Developer: Eli Lilly and Company
• Molecular weight: ~4,900 Da
• Research phase: Phase 3 clinical trials (as of 2026)

What Makes Retatrutide Different from Semaglutide and Tirzepatide?

• Semaglutide — single GLP-1 receptor agonist
• Tirzepatide — dual GLP-1 + GIP receptor agonist
• Retatrutide — triple GLP-1 + GIP + glucagon receptor agonist

The addition of glucagon receptor agonism is what distinguishes retatrutide in research. Glucagon receptor activation increases energy expenditure and hepatic fat metabolism — mechanisms not present in semaglutide or tirzepatide. Phase 2 research data showed mean weight reduction of 24.2% at 48 weeks in study participants, the highest figure observed in any incretin-class research peptide to date.

Retatrutide Research Status

As of 2026, retatrutide is in Phase 3 SURMOUNT clinical trials. It has not received FDA approval for any indication. Phase 2 results were published in the New England Journal of Medicine (2023). All preclinical and research use of retatrutide is conducted in laboratory settings only.

Frequently Asked Questions

Q: Is retatrutide FDA approved?
A: No. Retatrutide is currently in Phase 3 clinical trials and has not received FDA approval for any therapeutic use.

Q: How does retatrutide compare to tirzepatide in research?
A: Phase 2 data showed retatrutide producing greater mean weight reduction (24.2%) compared to tirzepatide's Phase 3 SURPASS data (~22.5%), though direct head-to-head trial data is not yet available.

Q: What receptors does retatrutide target?
A: Retatrutide is a triagonist targeting GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide), and glucagon receptors simultaneously.

Related research compounds: Retatrutide Research Peptide | Tirzepatide Research Peptide | Semaglutide Research Peptide

Further reading: Complete Retatrutide Research Guide | 2026 Phase 3 Trial Updates

All content on this page is for informational and educational purposes only. These statements have not been evaluated by the Food and Drug Administration. For laboratory research use only. Not for human consumption.