Lipitor (atorvastatin) is a medication used to lower cholesterol levels and reduce the risk of heart disease [1]. According to the Mayo Clinic, some of the common side effects of Lipitor include headache, diarrhea, joint pain, and muscle pain [2]. However, the time of day when Lipitor is taken does not appear to have any significant impact on the occurrence of these side effects [2][3].

While there is some evidence to suggest that taking Lipitor at night may result in a slightly greater reduction in cholesterol levels compared to taking it in the morning, this difference is generally considered to be small and may not be clinically significant for all patients [3]. Therefore, the decision to take Lipitor at night should be based on individual patient preferences and factors such as convenience and adherence to medication schedules, rather than any significant differences in effectiveness or side effects [3].

In summary, Lipitor is a medication used to lower cholesterol levels and reduce the risk of heart disease. While it may cause side effects such as headache, diarrhea, joint pain, and muscle pain, the time of day when it is taken does not appear to have any significant impact on the occurrence of these side effects. While taking Lipitor at night may result in a slightly greater reduction in cholesterol levels compared to taking it in the morning, this difference is generally considered to be small and may not be clinically significant for all patients [2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/side-effects/drg-20067003
[3] https://www.drugs.com/medical-answers/does-lipitor-work-better-if-you-take-it-at-night-416127/