Retatrutide is an investigational treatment for obesity from Eli Lilly. It is a triple hormone receptor agonist: a gastric inhibitory polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and glucagon receptor agonist.

• Obesity is a complex disease that occurs when an individual's weight is higher than what is considered healthy for his/her height. According to the CDC, people with a body mass index (BMI) between 25 and 29.9 are considered overweight, and people with a BMI of 30 or higher are considered obese.
• 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 released from the gut after eating. It stimulates the beta-cells in the pancreas to secrete insulin.
• GLP-1 (glucagon-like peptide-1) is 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.
• The drug has been nicknamed 'triple G' because it is an agonist of all three receptors.
• Phase 2 clinical trial results published in The New England Journal of Medicine show Retatrutide achieved up to 17.5% mean weight reduction at 24 weeks in adults with obesity and overweight. In a secondary endpoint, Retatrutide demonstrated a mean weight reduction up to 24.2% at 48 weeks.
• Retatrutide is an injection that is administered once a week.
• Retatrutide is also being studied for the treatment of type 2 diabetes mellitus.