Retatrutide
Also known as: LY3437943, Triple-G agonist
Overview
Retatrutide (LY3437943) is a novel triple receptor agonist developed by Eli Lilly that simultaneously activates GLP-1, GIP, and glucagon receptors. It represents the next generation of incretin-based therapies beyond dual agonists like tirzepatide. Phase 2 trial results published in 2023 showed unprecedented weight loss outcomes, making it one of the most closely watched compounds in obesity medicine.
Mechanism of Action
By co-activating GLP-1, GIP, and glucagon receptors, retatrutide creates additive and synergistic metabolic effects. GLP-1 agonism suppresses appetite and slows gastric emptying. GIP agonism enhances insulin secretion and may improve the tolerability of GLP-1-driven weight loss by reducing nausea. Glucagon agonism increases energy expenditure and hepatic fat mobilisation, contributing additional weight loss beyond GLP-1/GIP dual agonism.