Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels and reduce the risk of heart disease. According to the NHS [2], Lipitor should be taken once a day, at the same time each day, with or without food. However, Drugs.com [3] recommends taking Lipitor with food to improve its absorption and reduce the risk of side effects. The absorption of atorvastatin is not affected by food, but taking it with a meal can help prevent stomach upset [3]. It is important to follow the instructions provided by your doctor or pharmacist regarding the timing and dosage of Lipitor to ensure its effectiveness and minimize any potential side effects.

Sources:
[2] https://www.nhs.uk/medicines/atorvastatin/how-and-when-to-take-atorvastatin/
[3] https://www.drugs.com/medical-answers/eat-food-taking-atorvastatin-3565628/