Retatrutide

Overview

Retatrutide (Eli Lilly code LY3437943) is an investigational triple-receptor agonist simultaneously targeting GLP-1, GIP, and glucagon receptors. It is research-only and NOT FDA-approved as of April 2026; the Phase 3 TRIUMPH program is ongoing with anticipated NDA filing in 2026. Published Phase 2 data showed roughly 24% mean body weight loss at 48 weeks on 12 mg weekly (Jastreboff, NEJM 2023).

Mechanism of Action

Simultaneously activates three incretin and metabolic receptors: GLP-1R (glucose-dependent insulin secretion, appetite suppression, delayed gastric emptying), GIPR (insulin sensitization, adipose fat metabolism), and glucagon receptor (hepatic glucose output, thermogenesis, fatty acid oxidation). The glucagon-receptor component increases resting energy expenditure and hepatic fat mobilization — a mechanism absent in GLP-1 monotherapy and dual GLP-1/GIP agonists like tirzepatide. Half-life is approximately 6 days, enabling once-weekly subcutaneous dosing.

Research Summary

Phase 2 obesity trial (Jastreboff et al., NEJM 2023; PMID 37366315) demonstrated up to 24.2% body weight loss at 48 weeks at the 12 mg dose, exceeding both semaglutide and tirzepatide. A Phase 2 type 2 diabetes trial (Rosenstock et al., Lancet 2023; PMID 37385280) showed robust HbA1c and weight reductions vs. placebo and dulaglutide. A Phase 2a MASLD trial (Sanyal et al., Nat Med 2024; PMID 38858523) demonstrated significant reductions in hepatic steatosis driven by glucagon receptor activation. Phase 3 TRIUMPH trials are ongoing (Eli Lilly), with results expected 2025–2026. Retatrutide is NOT FDA-approved as of April 2026 — it remains investigational.

Vendors selling Retatrutide

Scored vendors carrying Retatrutide, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer Retatrutide

34 prescribers in our directory work with Retatrutide, each confirmed from their own website. Peptides like Retatrutide require a prescription from a licensed provider.

Reported Side Effects

• Nausea and vomiting
• Diarrhea
• Decreased appetite
• Constipation
• Injection site reactions
• Increased heart rate

Biomarkers researchers track for Retatrutide

These biomarkers appear in the research literature as measures of response and safety for this compound.

Related Peptides

Research Guides

• Cheapest verified Retatrutide: live prices, vendors & COA data

Compare Retatrutide with Others

Research References

• Jastreboff AM, et al. Triple-hormone-receptor agonist retatrutide for obesity — a Phase 2 trial. NEJM. 2023;389(6):514-526. PMID: 37366315.
• Rosenstock J, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a Phase 2 trial. The Lancet. 2023;402(10401):529-544. PMID: 37385280.
• Sanyal AJ, et al. Triple hormone receptor agonist retatrutide for MASLD: a Phase 2a trial. Nature Medicine. 2024;30(7):2037-2048. PMID: 38858523.

Frequently asked questions

Has Retatrutide been independently lab-tested?

Disclosed Labs has collected 455 Certificates of Analysis (COA) for Retatrutide from 19 independent testing labs. 60 vendors have submitted material for testing. Products average 99.7% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/retatrutide/testing.

What is the average purity of Retatrutide on the market?

Based on 455 COAs analyzed by Disclosed Labs, Retatrutide products average 99.7% (±0.3%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/retatrutide/coas.

Which labs have tested Retatrutide?

Independent labs that have tested Retatrutide include: ILS Labs (Grade A), Ethos Analytics (Grade B). Full lab credibility grades and profiles are at https://www.disclosedlabs.com/labs.

Where can researchers source Retatrutide?

8 vendors with Disclosed Labs trust grades currently list Retatrutide, including Glacier Aminos, Voltera Sciences, Ion Peptide. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/retatrutide.

Which prescribers offer Retatrutide with a prescription?

34 prescribers in the Disclosed Labs directory work with Retatrutide, each confirmed from their own website. Retatrutide requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=Retatrutide.

How does Retatrutide work?

Simultaneously activates three incretin and metabolic receptors: GLP-1R (glucose-dependent insulin secretion, appetite suppression, delayed gastric emptying), GIPR (insulin sensitization, adipose fat metabolism), and glucagon receptor (hepatic glucose output, thermogenesis, fatty acid oxidation). The glucagon-receptor component increases resting energy expenditure and hepatic fat mobilization — a mechanism absent in GLP-1 monotherapy and dual GLP-1/GIP agonists like tirzepatide. Half-life is approximately 6 days, enabling once-weekly subcutaneous dosing.

What does the research say about Retatrutide?

Phase 2 obesity trial (Jastreboff et al., NEJM 2023; PMID 37366315) demonstrated up to 24.2% body weight loss at 48 weeks at the 12 mg dose, exceeding both semaglutide and tirzepatide. A Phase 2 type 2 diabetes trial (Rosenstock et al., Lancet 2023; PMID 37385280) showed robust HbA1c and weight reductions vs. placebo and dulaglutide. A Phase 2a MASLD trial (Sanyal et al., Nat Med 2024; PMID 38858523) demonstrated significant reductions in hepatic steatosis driven by glucagon receptor activation. Phase 3 TRIUMPH trials are ongoing (Eli Lilly), with results expected 2025–2026. Retatrutide is NOT FDA-approved as of April 2026 — it remains investigational.