Retatrutide activates three receptors at once — GIP, GLP-1, and glucagon — the broadest mechanism yet studied in this class. The added glucagon activity is thought to increase energy expenditure and hepatic fat oxidation on top of the appetite-suppressing, glucose-lowering effects shared with GLP-1 and dual agonists. Phase 3 data through mid-2026 have shown weight loss in the high-20s percent range at 68–80 weeks — among the largest reported for any pharmacologic agent.

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• TRIUMPH Phase 3 program: obesity, knee osteoarthritis, obstructive sleep apnea
• TRANSCEND Phase 3 program: type 2 diabetes
• Not currently accessible outside of clinical trials in the US

• First and only agent studied with triple GIP/GLP-1/glucagon agonism — one mechanistic step beyond tirzepatide's dual action
• Glucagon component raises resting heart rate modestly, a factor under close regulatory review
• Not on the FDA's list of compoundable bulk substances — unlike semaglutide and tirzepatide during their shortage periods, retatrutide cannot legally be compounded