Retatrutide is an investigational treatment for obesity that is a triple hormone receptor agonist. Retatrutide is a gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and glucagon receptor agonist. Retatrutide works in the treatment of obesity by targeting three different hunger regulating hormones: • GIP (gastric inhibitory peptide or glucose-dependent insulinotropic polypeptide) is an incretin hormone that is released from the gut after eating. It stimulates the beta-cells in the pancreas to secrete insulin. • GLP-1 (glucagon-like peptide-1) is also an incretin hormone that stimulates the beta-cells to secrete insulin. • Glucagon is a hormone secreted from the alpha-cells in the pancreas. It stimulates glucose production in the liver and helps maintain adequate plasma glucose concentrations.