Mazdutide: A Beginner's Guide to the First GLP-1/Glucagon Dual Agonist
What Is Mazdutide? I've been getting asked to cover it so here's everything you need to know. Mazdutide is a next-generation peptide that targets two receptors instead of just one. While semaglutide (Ozempic/Wegovy) only hits the GLP-1 receptor, and tirzepatide (Mounjaro/Zepbound) hits GLP-1 and GIP. Mazdutide takes a different approach: GLP-1 + Glucagon (GCG) This makes it the world's first approved dual GLP-1/glucagon receptor agonist. How Does It Work? (Simple Version) Think of mazdutide as having two engines working together: Engine 1: GLP-1 Activation - Reduces appetite and cravings - Slows gastric emptying (food stays in your stomach longer) - Promotes insulin secretion - This is the same mechanism as semaglutide Engine 2: Glucagon Activation - Increases energy expenditure (you burn more calories) - Improves fat metabolism in the liver - Helps reduce liver fat content The glucagon component is what makes mazdutide unique. While it might seem counterintuitive (glucagon raises blood sugar, right?), when combined with GLP-1, the insulin-promoting effects dominate while you still get the metabolic boost from glucagon activation. The result: You eat less AND burn more. Plus significant improvements in liver fat, which most GLP-1s alone don't address as effectively. Who Makes It? The Story Eli Lilly originally developed mazdutide (also called LY3305677 or IBI362). It's actually an analog of oxyntomodulin—a natural hormone your gut produces after eating that activates both GLP-1 and glucagon receptors. In 2019, Lilly licensed the China rights to Innovent Biologics, a Chinese biopharma company. Innovent ran all the major clinical trials and pushed it through approval. June 2025: China's NMPA approved mazdutide for chronic weight management—making it the world's first approved GLP-1/glucagon dual agonist. Lilly still holds the rights outside China and is running Phase 2 trials in the US, but Innovent has been the driving force behind its development.