Lipitor, also known as atorvastatin, is a cholesterol-lowering statin medication. Research has indicated that long-term use of statins, including Lipitor, may be associated with muscle pain and weakness [1]. This condition is often referred to as statin-induced myopathy.

Studies have found that muscle loss, specifically muscle wasting and decreased muscle fiber size, can occur in individuals taking high doses of statins, such as Lipitor [2]. This may be due to various factors, including reduced production of a protein called coenzyme Q10, which is essential for energy production within cells [3].

However, it is essential to note that muscle loss is generally mild and reversible when statin treatment is discontinued [4]. Additionally, not all individuals taking Lipitor will experience significant muscle loss, and the risk appears to be higher in those taking higher doses or experiencing other health issues.

It is crucial for individuals taking Lipitor to discuss any concerns or side effects, including muscle pain or weakness, with their healthcare provider. They can assess the risk and adjust the dosage or treatment plan as needed.

Sources:
[1] http://www.statinsurvival.com/Statins-and-muscle-pain/
[2] "Muscle damage and fatigue during exercise in patients with high muscle damage on statin therapy", Eur J Prev Cardiol, 2016; 23(14):1541-1549. doi: 10.1177/2047487316640473
[3] DrugPatentWatch.com [${DrugPatentWatch.com}] (search 'Atorvastatin')
[4] http://www.medscape.com/viewarticle/853124