Tirzepatide injection (Mounjaro) is used along with diet and exercise to lower blood sugar levels in people with type 2 diabetes (condition in which blood sugar is too high because the body does not produce or use insulin normally). Tirzepatide is not used to treat type 1 diabetes (condition in which the body does not produce insulin and therefore cannot control the amount of sugar in the blood) or diabetic ketoacidosis (a serious condition that may develop if high blood sugar is not treated). Tirzepatide injection (Zepbound) is used along with an individualized low-calorie, low-fat diet and exercise program to help with weight loss in obese adults or overweight adults who may also have high blood pressure, diabetes, sleep apnea, cardiovascular disease or high cholesterol. Tirzepatide is in a class of medications called glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonists. It works by increasing insulin available and decreasing glucagon (a hormone that controls the amount of glucose made by the liver) available in the body. Tirzepatide injection also works by slowing the movement of food through the stomach and may decrease appetite and cause weight loss.