Triple agonist (GLP-1/GIP/glucagon) for exceptional weight loss — the most potent investigational obesity drug to date.
Retatrutide (LY3437943) is an investigational once-weekly injectable drug developed by Eli Lilly that targets three glucagon-related receptors simultaneously: GLP-1, GIP, and glucagon receptors. This tri-agonist approach distinguishes it from semaglutide (single GLP-1 agonist) and tirzepatide (dual GLP-1/GIP agonist).
Early Phase 2 clinical trials have shown exceptionally strong weight-loss results — with some participants losing over 24% of body weight over 48 weeks at the highest dose, making it the most potent anti-obesity compound in clinical development as of 2024.
Retatrutide promotes weight loss through simultaneous agonism of three receptors:
The combined effect of appetite suppression, improved insulin sensitivity, and increased energy expenditure produces greater weight loss than dual-agonist approaches.
Phase 2 data (n=338): mean weight reduction of 17.5% at 12 mg dose and 24.2% at the highest dose tested over 48 weeks. Superior glycemic improvements vs. placebo. Ongoing Phase 3 trials (TRIUMPH program).
GI side effects (nausea, vomiting, diarrhea) — class effect common to GLP-1 agonists, dose-dependent. Mild heart rate increase (1–3 bpm). Injection site reactions. Not yet approved; long-term safety profile under investigation.
Clinical trial doses: 0.5–12 mg/week via subcutaneous injection. Titration from 0.5 mg, escalating every 4 weeks. Research use only — not approved for human use outside clinical trials.