Based on the information available, there is no definitive evidence to suggest that Lipitor, a medication commonly used to treat high cholesterol, directly weakens muscle strength [1]. However, it is important to note that some people taking Lipitor (atorvastatin) may experience muscle-related side effects.

These side effects can include muscle pain, cramps, and weakness, but these symptoms are typically mild and do not lead to a significant decrease in muscle strength [2]. In rare cases, a condition called rhabdomyolysis can occur, which is characterized by the breakdown of muscle tissue and the release of muscle fiber contents into the bloodstream [2]. This can lead to serious complications, such as kidney damage, but it is a very uncommon side effect [2].

It is crucial to report any muscle-related symptoms to a healthcare provider while taking Lipitor, as they may indicate a more serious issue [2]. Factors that may increase the risk of muscle-related side effects include taking higher doses of Lipitor, being older, having kidney or liver problems, and combining Lipitor with certain other medications [2].

In conclusion, while Lipitor may be associated with muscle-related side effects, there is no clear evidence to suggest that it directly weakens muscle strength in most individuals. Always consult with a healthcare provider for personalized medical advice.

Sources:
[1] DrugPatentWatch.com. (n.d.). Atorvastatin (Lipitor). Retrieved from https://www.drugpatentwatch.com/drugs/atorvastatin
[2] Mayo Clinic. (2021, April 2). Atorvastatin (Oral Route). Retrieved from https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20069056?p=1