Incretin Axis
The incretin axis encompasses GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic polypeptide), gut hormones released in response to nutrient intake that account for roughly 70% of postprandial insulin secretion. Drugs targeting this axis include single GLP-1 agonists (semaglutide), dual GLP-1/GIP agonists (tirzepatide), and triple GLP-1/GIP/glucagon agonists (retatrutide). The axis is the largest commercial pharma category of the 2020s and is responsible for the metabolic-medicine revolution underway in obesity, type 2 diabetes, and cardiometabolic disease.
