Retatrutide

Retatrutide (LY3437943) is an investigational, once-weekly injectable peptide developed by Eli Lilly. It is a first-in-class "triple agonist" that simultaneously activates the GIP, GLP-1, and glucagon receptors. The glucagon-receptor component is the main feature distinguishing it from dual agonists like tirzepatide, and is thought to add an energy-expenditure effect on top of appetite suppression. In a 48-week phase 2 obesity trial (NEJM, 2023), the highest 12 mg dose produced a mean weight reduction of about 24.2%, among the largest reductions reported for any pharmacologic obesity agent in trials to date. A separate phase 2a trial showed marked reductions in liver fat in people with metabolic dysfunction-associated steatotic liver disease (MASLD). Eli Lilly's phase 3 TRIUMPH program is ongoing. As of mid-2026, retatrutide is NOT approved by the FDA, EMA, or any major regulator and remains an experimental compound under clinical investigation. The European Medicines Agency (EMA) has not authorised retatrutide, and Helica supplies it strictly for research use, dispatched from a warehouse within the EU. Material sold by research-chemical vendors is unregulated, not pharmaceutical-grade, and is labeled research-use-only. The data below summarizes published evidence and clearly separates clinical findings from anecdotal community use.