Illustration showing the molecular structure of tirzepatide, a drug used to treat type 2 diabetes and obesity. 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. Atoms are represented as rods and are colour-coded: carbon (grey), nitrogen (blue) and oxygen (red).