Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels and reduce the risk of heart disease [1]. According to a study published in the Journal of Clinical Lipidology, statins like Lipitor have been shown to have potential side effects on muscle function, including muscle pain and weakness [2]. However, a more recent study published in the Journal of the American Heart Association found that statins do not worsen muscle pain or fatigue during moderate exercise [3].

While there is evidence to suggest that Lipitor can cause muscle-related side effects, including fatigue during exercise, the severity of these side effects can vary from person to person. It is important to note that the benefits of taking Lipitor in reducing the risk of heart disease often outweigh the potential risks of side effects. If you are experiencing fatigue during exercise while taking Lipitor, it is recommended that you speak with your healthcare provider to determine the best course of action.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4679305/
[3] https://www.healthline.com/health-news/statins-wont-worsen-muscle-pain-or-fatigue-during-moderate-exercise-study-finds