Lipitor, also known as atorvastatin, is a medication used to lower cholesterol levels in the body. According to the British Heart Foundation [2], it may take up to two weeks to see a noticeable effect on cholesterol levels. However, the full effect of the medication may take up to four weeks or longer to achieve. This is because the medication works by blocking an enzyme in the liver that produces cholesterol. As a result, it takes time for the body to adjust and for the medication to take full effect.

It is important to note that the time it takes for Lipitor to take effect may vary from person to person, depending on factors such as age, weight, and overall health. Additionally, it is essential to follow the prescribed dosage and continue taking the medication as directed by a healthcare provider.

Sources:
[2] British Heart Foundation. (n.d.). Statins. Retrieved from https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/statins
[3] Drugwatch. (2021, February 10). Lipitor. Retrieved from https://www.drugwatch.com/lipitor/