Retatrutide

Retatrutide (development code LY3437943) is an investigational metabolic drug developed by Eli Lilly and Company. It has attracted attention because it activates three hormone receptors simultaneously—GIP, GLP-1, and glucagon—rather than targeting only GLP-1 or the GIP/GLP-1 combination used by some existing medicines.

How retatrutide works

The three receptor targets have complementary metabolic effects. GLP-1 receptor activation can reduce appetite, increase feelings of fullness, slow gastric emptying, and improve glucose-dependent insulin secretion. GIP receptor activation also affects insulin secretion and energy regulation and may complement GLP-1 signaling. Glucagon receptor activation is the unusual third component; researchers believe it may influence energy expenditure, fat metabolism, and substrate utilization. The idea is that combining all three pathways could produce greater effects on body weight and metabolic health than targeting one pathway alone.