Lipitor is a brand name for the drug atorvastatin, which is a medication used to lower cholesterol levels in the body. While Lipitor can be effective in treating high cholesterol, it may also cause some side effects.

According to the NHS [2], common side effects of atorvastatin (Lipitor) include headache, feeling sick, diarrhea, constipation, and stomach pain. Additionally, some people may experience muscle pain, weakness, or tenderness, as well as an increase in blood sugar levels.

The Mayo Clinic [3] also notes that atorvastatin may cause liver problems, which can lead to symptoms such as yellowing of the skin or eyes, dark urine, and abdominal pain. In rare cases, atorvastatin may also cause a condition called rhabdomyolysis, which is a breakdown of muscle tissue that can lead to kidney damage.

It is important to note that not everyone who takes atorvastatin will experience these side effects, and some people may not experience any side effects at all. However, if you do experience any of these symptoms while taking Lipitor, it is important to speak with your doctor.

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