Lipitor, a medication commonly used to treat high cholesterol, is known to have potential side effects. However, according to the information provided and the research conducted, lip stiffness is not explicitly listed as a common side effect of Lipitor [1].

The most common side effects of Lipitor include muscle pain, liver problems, and digestive issues such as diarrhea, constipation, and gas [1]. It is crucial to consult with a healthcare provider or pharmacist for a comprehensive list of potential side effects and to understand the risks and benefits associated with this medication.

Always report any unusual symptoms or persistent side effects to a healthcare professional. It is important to note that everyone's reaction to a medication can vary, and some people may experience side effects not listed here or in the medication's patient information leaflet.

Sources:
[1] DrugPatentWatch.com - Lipitor (Atorvastatin) Side Effects (Accessed on March 22, 2023) - <https://www.drugpatentwatch.com/drugs/lipitor>