The level of blood cholesterol in a living animal body in which a state of hypercholesterolemia exists is lowered by orally administering to said animal body a pharmaceutically effective amount of a polymer, which is (1) polymerized unsaturated carboxylic acid or anhydride, or (2) a copolymer of (a) an unsaturated monomer having, for Example, 2 to 30 carbon atoms and, (b) an unsaturated carboxylic acid, anhydride or derivative thereof as exemplified by octadecene-1/maleic anhydride copolymer. Polymers having lipophilic properties are a preferred class. A typical dosage is an amount which represents in the range of from about 0.01 to about 5.0% of the diet.