According to the sources provided, dehydration is not listed as a common side effect of Lipitor (atorvastatin), a medication used to lower cholesterol levels. The most common side effects of Lipitor include headache, muscle pain, joint pain, diarrhea, and nausea [2][3]. However, it is important to note that everyone reacts differently to medication, and some individuals may experience uncommon or rare side effects. If you have concerns about dehydration or any other side effects while taking Lipitor, it is recommended to speak with your healthcare provider [2][3].

Sources:
[2] https://www.healthline.com/health/drugs/atorvastatin-oral-tablet
[3] https://www.nhs.uk/medicines/atorvastatin/side-effects-of-atorvastatin/