Lipitor is a brand name for atorvastatin, a medication used to lower cholesterol levels in the blood. While Lipitor is generally well-tolerated, it can cause some side effects. The most common side effects of Lipitor are muscle pain and digestive problems such as nausea, diarrhea, and constipation [2][3]. In rare cases, Lipitor can cause serious side effects such as liver damage, muscle breakdown, and a rare but serious condition called rhabdomyolysis, which can cause kidney damage [2]. Some patients may also experience allergic reactions such as rash, hives, and difficulty breathing [2]. It is important to note that the severity and frequency of side effects can vary from person to person [3]. Patients who experience any unusual symptoms while taking Lipitor should contact their doctor immediately [3]. Overall, Lipitor is generally well-tolerated and effective in lowering cholesterol levels in the blood [1].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003
[3] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/