Lipitor is a medication that is used to lower cholesterol levels in the body. According to the sources provided, it can take several weeks for Lipitor to take effect.

Healthline [1] states that it may take up to two weeks for patients to see a reduction in their cholesterol levels. This is because Lipitor works by blocking an enzyme in the liver that is responsible for producing cholesterol. As the liver produces less cholesterol, the body's cholesterol levels begin to decrease.

The British Heart Foundation [3] also confirms that it can take several weeks for statins, including Lipitor, to take effect. The foundation explains that patients may need to have their cholesterol levels checked after four to six weeks of starting treatment to determine if the medication is working.

Drug Patent Watch [2] provides additional information on Lipitor, including its mechanism of action and dosage information. According to the website, Lipitor is typically taken once a day, with or without food. The dosage may vary depending on the patient's age, medical history, and other factors.

In conclusion, based on the sources provided, it can take up to two weeks or more for Lipitor to take effect and lower cholesterol levels in the body. Patients may need to have their cholesterol levels checked after four to six weeks of starting treatment to determine if the medication is working. It is important to follow the prescribed dosage and consult with a healthcare provider if there are any concerns or questions about the medication.

Sources:
[1] https://www.healthline.com/health/drugs/lipitor
[2] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[3] https://www.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/statins