Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the body. According to the sources provided, Lipitor should be taken once a day, with or without food, at the same time every day [2][3]. It is recommended to take Lipitor with a full glass of water [2]. The dose of Lipitor prescribed by a healthcare provider may vary depending on the patient's condition, age, and other factors [1]. It is important to follow the instructions given by the healthcare provider regarding the frequency and dosage of Lipitor [3].

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.mayoclinic.org/drugs-supplements/atorvastatin-oral-route/proper-use/drg-20067003