Based on the information provided, there is no explicit mention of stiffness as a side effect of taking Lipitor (Atorvastatin) [1]. However, it is known that statins like Lipitor can cause muscle-related side effects [3]. The Mayo Clinic states that one possible side effect of statins is muscle pain, weakness, or damage [2]. This condition, known as rhabdomyolysis, can cause muscle stiffness, among other symptoms [2].

It is essential to note that not everyone who takes Lipitor will experience muscle stiffness or any other side effects. If you notice stiffness or other unusual symptoms after starting Lipitor, it is recommended to consult with a healthcare professional [3]. They can evaluate your symptoms and determine whether Lipitor is the appropriate medication for you.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expert-answers/rhabdomyolysis/faq-20057817
[3] https://www.goodrx.com/classes/statins/muscle-pain-statins-how-to-prevent-common-side-effect