Cholestyramine resin is used as a lipid-lowering agent in the treatment of hypercholesterolemia and also for managing pruritus associated with partial biliary obstruction. It is also used in pharmaceutical quality control as a drug substance for formulation and analytical testing including assay and identification.

Its primary purpose is to bind bile acids in the gastrointestinal tract to form insoluble complexes thereby preventing their reabsorption and increasing their excretion from the body.

Cholestyramine resin is a strongly basic anion-exchange resin containing quaternary ammonium functional groups. It is a high-molecular-weight water-insoluble polymer that exists as a resinous powder or granules.