Retatrutide

Retatrutide (LY3437943) is a novel acylated peptide that acts as a triple agonist at the glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon receptors. This multi-receptor engagement profile distinguishes it from dual agonists such as tirzepatide and single agonists such as semaglutide, providing researchers with a unique tool to study the combined contributions of these three incretin and glucagon pathways to energy homeostasis, glucose metabolism, and body composition. Structurally, retatrutide incorporates a C18 fatty diacid moiety attached via a linker to enable extended half-life through albumin binding, supporting once-weekly dosing regimens in preclinical and clinical study designs. The balanced agonism across all three receptors is thought to produce complementary and synergistic effects: GLP-1 receptor activation suppresses appetite and slows gastric emptying; GIP receptor activation enhances insulin secretion and may modulate adipose tissue metabolism; glucagon receptor activation increases energy expenditure and hepatic glucose output. Research published in the New England Journal of Medicine (2023) reported substantial reductions in body weight in participants with obesity, with some cohorts achieving mean weight reductions exceeding 20% over 48 weeks. These findings have positioned retatrutide as a significant subject of investigation in the study of metabolic syndrome, non-alcoholic fatty liver disease (NAFLD), and type 2 diabetes pathophysiology. As a lyophilized research peptide, it is supplied for in vitro and preclinical research use only.