Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the body. While joint pain is listed as a potential side effect of Lipitor [2], there is no clear evidence to suggest that it reduces joint flexibility. In fact, a study published in the Journal of Clinical Lipidology found that atorvastatin did not have a significant impact on joint pain or function in patients with osteoarthritis [3]. However, it is important to note that every individual may react differently to medications, and joint pain is a known side effect of statins like Lipitor [1]. If you are experiencing joint pain or stiffness while taking Lipitor, it is important to talk to your doctor to determine the best course of action.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/classes/statins/joint-pain
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463373/