Lipitor, also known as atorvastatin, is a commonly prescribed medication used to lower cholesterol levels in the body [1]. One of the possible side effects of this medication is muscle weakness or pain, especially during exercise [2]. According to a study published in the Journal of Pharmacy Practice, muscle weakness is a rare but possible side effect of statins, including Lipitor [3].

Muscle pain and weakness are the most commonly reported side effects of statins, and these symptoms can range from mild discomfort to severe muscle damage [2]. In some cases, the muscle damage can lead to a condition called rhabdomyolysis, which can cause kidney damage and even be life-threatening [2].

It is important to note that not everyone who takes Lipitor will experience muscle weakness or pain, and the risk of these side effects may be higher in certain individuals, such as those who are older, have kidney or liver disease, or are taking certain other medications [2]. If you experience muscle weakness or pain while taking Lipitor, it is important to talk to your doctor, who may adjust your dosage or switch you to a different medication [2].

In conclusion, Lipitor can cause muscle weakness during exercise as a possible side effect, although it is rare. If you experience muscle weakness or pain while taking Lipitor, it is important to speak with your doctor to determine the best course of action [2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statin-side-effects/art-20046013
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3463373/