Atorvastatin (INN) ( ), marketed under the trade name Lipitor and several others, is a member of the drug class known as statins, used for lowering cholesterol. Atorvastatin inhibits the rate-determining enzyme located in hepatic tissue that produces mevalonate, a small molecule used in the synthesis of cholesterol and other mevalonate derivatives. This lowers the amount of cholesterol produced which in turn lowers the total amount of LDL cholesterol.

With 2006 sales of US$12.9 billion under the brand name Lipitor, it is the largest selling drug in the world.

Lipitor is not the only statin. There are over 5 other statins in the market.