Lipitor is a lipid-regulating drug belonging to the statin class and is a prodrug dosage form. Lipitor competitively inhibits the key enzyme of bone alcohol synthesis in the body and reduces the activity of this enzyme, thus blocking the production of cholesterol, and also upregulates the LDL receptors on the cell surface to accelerate the breakdown and metabolism of LDL in plasma. Lipitor mainly lowers serum total cholesterol, LDL cholesterol, and to some extent triglycerides and very low-density lipoprotein cholesterol, and mildly raises the level of good lipoprotein, HDL cholesterol. Lipitor is mainly used in hypercholesterolemia, as well as in mixed hyperlipidemia with predominantly elevated cholesterol. Lipitor is one of the more widely used statin drugs and can be taken at any time of the day. The side effects of Lipitor are relatively minor, but a few people may experience abdominal pain, constipation, insomnia, increased transaminases, muscle pain, elevated serum creatine kinase, and in a very few severe cases, rhabdomyolysis, leading to acute renal failure. Adverse reactions may increase when Lipitor is combined with other lipid-regulating drugs, such as beta-nicotinic acid, so care must be taken when combining them. Also, be aware that it is not recommended for use in children, pregnant women, women who are breastfeeding, or women who are preparing to have children.