Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels and reduce the risk of heart disease and stroke [1]. Like any medication, Lipitor may cause side effects. According to the NHS, common side effects of atorvastatin include headaches, stomach pain, constipation, and diarrhea [2]. The Mayo Clinic lists additional potential side effects, including muscle pain, weakness, and tenderness, liver damage, and an increased risk of developing type 2 diabetes [3]. However, it is important to note that not everyone who takes Lipitor will experience side effects, and many people are able to take the medication without any problems. If you are concerned about potential side effects of Lipitor, it is recommended that you speak with your doctor.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/
[3] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013