Cholestyramine is a bile acid sequestrant medication primarily used to lower cholesterol levels in the blood, especially low-density lipoprotein (LDL or “bad” cholesterol). It works by binding to bile acids in the intestines, preventing their reabsorption. This forces the liver to use more cholesterol to make new bile acids, thereby reducing circulating cholesterol levels.

In addition to treating high cholesterol, cholestyramine is sometimes prescribed for itching caused by partial bile duct obstruction and for managing certain cases of diarrhea, such as that related to bile acid malabsorption. It is usually taken as a powder mixed with water or juice, and common side effects can include constipation, bloating, and stomach discomfort.