Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. According to the NHS [2], it is recommended to take Lipitor once a day, at the same time each day, with or without food. However, the best time to take Lipitor is at bedtime, as stated by Drugs.com [3]. The reason for this is that the body produces more cholesterol at night, so taking Lipitor before bed helps to block the production of cholesterol more effectively. It is important to follow the instructions provided by your doctor or pharmacist regarding the dosage and timing of Lipitor. As per Drug Patent Watch [1], Lipitor is available in different strengths, and the dosage may vary depending on the individual's medical condition and response to treatment. It is essential to take Lipitor regularly to get the most benefit from it. If you miss a dose, take it as soon as you remember, but do not take a double dose to make up for a missed one. It is advisable to consult your doctor or pharmacist if you have any questions or concerns about taking Lipitor.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.nhs.uk/medicines/atorvastatin/how-and-when-to-take-atorvastatin/
[3] https://www.drugs.com/medical-answers/does-lipitor-work-better-if-you-take-it-at-night-416127/