A triple-agonist (GIP/GLP-1/glucagon) in late-stage clinical trials showing remarkable weight loss.
Retatrutide is an investigational peptide from Eli Lilly that simultaneously agonizes three receptors: GIP (glucose-dependent insulinotropic polypeptide), GLP-1 (glucagon-like peptide-1), and the glucagon receptor. This triple-agonist mechanism represents the next frontier beyond dual-agonists like tirzepatide.
The addition of glucagon receptor agonism is theoretically significant: glucagon increases energy expenditure and fat burning in the liver, complementing the appetite-suppressing and insulin-sensitizing effects of GIP/GLP-1. This combination may address obesity from multiple metabolic angles simultaneously.
As of 2024-2026, retatrutide is in Phase 3 clinical trials. It is NOT FDA-approved and is not available outside of clinical trials through legal channels. Any product claiming to be retatrutide for sale is unregulated.
Phase 2 trials (published in NEJM, 2023) showed extraordinary results: up to 24.2% average body weight reduction over 48 weeks at the highest dose โ surpassing even tirzepatide's SURMOUNT results. This would represent the highest weight loss ever seen from a pharmacological agent if confirmed in Phase 3.
The triple-agonist mechanism also showed significant reductions in liver fat, triglycerides, and blood pressure. Phase 3 trials are underway with results expected in 2025-2026. The cardiovascular outcomes and long-term safety profile are still being established.
๐ Key Reference: PMID: 37342922 (Phase 2 NEJM, 2023)
As an investigational drug, the full safety profile is not yet established. Phase 2 data showed similar GI side effects to GLP-1 agents (nausea, vomiting, diarrhea). Resting heart rate increases were observed. Long-term safety, including effects on thyroid, cardiovascular system, and bone density, requires Phase 3 evaluation. This drug should only be used within clinical trials.
NOT FDA-approved. Investigational New Drug (IND) status in clinical trials. Not legally available outside of registered clinical trials. Any product sold online as 'retatrutide' is unverified research chemical, not pharmaceutical-grade medication. Do not purchase or use.