Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the body. According to Drug Patent Watch , the recommended starting dose of Lipitor is 10 or 20 mg once daily, with the maximum dose being 80 mg once daily. However, the dose may vary depending on individual patient factors, such as age, gender, and medical history.
A study published in the National Center for Biotechnology Information  found that atorvastatin at a dose of 10 mg per day significantly reduced low-density lipoprotein (LDL) cholesterol levels in patients with hypercholesterolemia. The study also found that higher doses of atorvastatin (20-80 mg per day) were associated with greater reductions in LDL cholesterol levels.
It is important to note that while Lipitor can effectively lower cholesterol levels, it may also have side effects. According to Mayo Clinic , common side effects of statins (including Lipitor) include muscle pain and weakness, liver damage, and digestive problems. Patients taking Lipitor should talk to their healthcare provider about the appropriate dose and any potential side effects.