Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the blood. Joint pain is a common side effect of taking Lipitor, but it is not the only cause of joint pain. Other factors such as age, injury, or other medical conditions can also cause joint pain. According to GoodRx [2], statins, the class of drugs that Lipitor belongs to, are known to cause joint pain as a side effect. However, it is important to note that joint pain is not experienced by everyone who takes Lipitor, and some people may experience joint pain while taking other medications or due to other causes. If you are experiencing joint pain while taking Lipitor, it is recommended that you speak with your doctor to determine the cause and discuss potential treatment options.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/classes/statins/joint-pain
[3] https://www.drugwatch.com/lipitor/side-effects/