01 · mechanism of action
Retatrutide (LY3437943) is an experimental triple agonist that simultaneously activates GLP-1, GIP, and glucagon receptors — a previously unique combination in peptide research. In preclinical animal studies on obese mice and rats, retatrutide led to body-weight reductions of 20–30 % within 12 weeks, significantly stronger than semaglutide comparison groups. The combination of GLP-1 and glucagon agonism increased energy expenditure through thermogenic activation in brown adipose tissue. In Phase 1 and Phase 2 human studies (2022–2023) subjects showed weight reductions of up to 24 % of baseline over 48 weeks. Additional animal data show improvements in insulin sensitivity, reduction of hepatic fat (NASH models), and cardioprotective effects through improved lipid profiles.
