Lipitor is a prescription medication that contains a cholesterol-lowering medicine called atorvastatin. It is used to treat high cholesterol levels and reduce the risk of cardiovascular disease. Lipitor works by blocking HMG-CoA reductase, a liver enzyme that the body needs to produce low-density lipoproteins (LDL), or “bad” cholesterol. By lowering the amount of LDL in the blood, the medication prevents atherosclerosis, a condition in which plaque deposits accumulate on the inner walls of arteries, causing them to stiffen and narrow. Lipitor is also used to decrease the amount of fatty substances such as low-density lipoprotein (LDL) cholesterol and triglycerides in the blood and to increase the amount of high-density lipoprotein (HDL) cholesterol in the blood. It is prescribed in combination with a healthy diet for adults and certain children. Lipitor is for adults and children over 10 whose cholesterol does not come down enough with exercise and a low-fat diet alone.