Lipitor is a medication used to lower cholesterol levels in the body. The active ingredient in Lipitor is atorvastatin, which works by blocking an enzyme responsible for cholesterol production in the liver [1]. According to the Mayo Clinic, common side effects of Lipitor include muscle pain, weakness, and tenderness, which may be accompanied by fever or fatigue [2]. However, these side effects are typically mild and go away on their own after a few days or weeks. In rare cases, Lipitor may cause serious side effects such as liver damage, kidney problems, and a rare muscle condition called rhabdomyolysis [2][3]. These side effects are more likely to occur in individuals taking high doses of Lipitor or those with pre-existing medical conditions. It is important to speak with a healthcare provider before increasing the dosage of Lipitor or any other medication, as they can help determine the appropriate dosage and monitor for potential side effects [3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013
[3] https://www.healthline.com/health/drugs/lipitor