Illustration of tirzepatide (red, blue and grey spheres) bound to a glucagon-like peptide-1 (GLP-1) transmembrane receptor (beige vertical structure). Tirzepatide is a drug used to treat type 2 diabetes. It functions by mimicking glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) hormones, which are secreted in the gastrointestinal tract when we eat. They work by binding to GLP-1 and GIP receptors throughout the body and stimulating insulin secretion, inhibiting glucagon secretion, and slowing down gastric emptying. These effects all lower blood sugar levels, making tirzepatide a treatment option for type 2 diabetes.