What is Retatrutide?
Retatrutide (LY3437943) is an investigational triple-agonist peptide developed by Eli Lilly. It targets three receptors simultaneously: GLP-1, GIP, and glucagon. This triple mechanism is unique — the glucagon receptor activation is theorized to increase energy expenditure and fat oxidation beyond what dual agonists like tirzepatide achieve.
Clinical Trial Results
In a Phase 2 trial published in the New England Journal of Medicine (2023), participants on the 12 mg dose of retatrutide lost an average of 24.2% of body weight over 48 weeks — the highest percentage seen in any obesity drug trial to date. The Phase 3 program is currently underway with results expected in 2025–2026.
How to Reconstitute Retatrutide
As an investigational compound, retatrutide is available only through research channels. Reconstitution follows standard peptide protocols.
- 10 mg vial → 1 mL BAC water (10 mg/mL)
- 15 mg vial → 1.5 mL BAC water (10 mg/mL)
Titration
Clinical trials used a gradual escalation: 1 mg → 2 mg → 4 mg → 8 mg → 12 mg, with each step lasting 4 weeks. GI side effects were dose-dependent and similar in nature to semaglutide and tirzepatide.
Important Considerations
Retatrutide is NOT FDA-approved and is not available through standard pharmaceutical channels. Any research use should be conducted with full awareness of the investigational status of this compound. Long-term safety data beyond 48 weeks is not yet available.
Investigational compound. NOT FDA-approved. Educational purposes only.