Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the blood. According to the sources provided, it may take several weeks or even months for Lipitor to show results in reducing cholesterol levels.

The first source, Drug Patent Watch [1], provides information on the patent expiration of Lipitor, but does not provide any information on how long it takes for the drug to show results.

The second source, WebMD [2], explains that cholesterol-lowering medications like Lipitor work by reducing the amount of cholesterol produced by the liver. However, it may take several weeks or even months for the drug to have a noticeable effect on cholesterol levels. The article also notes that lifestyle changes, such as a healthy diet and exercise, can help to speed up the process.

The third source, NHS [3], provides more specific information on the timeline for Lipitor to show results. According to the website, it may take up to four weeks for patients to see a reduction in their cholesterol levels after starting Lipitor. However, the full effect of the drug may not be seen for up to 12 weeks.

In summary, Lipitor may take several weeks or even months to show results in reducing cholesterol levels. Patients may start to see a reduction in their cholesterol levels after four weeks of taking the drug, but it may take up to 12 weeks for the full effect to be seen. It is important to note that lifestyle changes, such as a healthy diet and exercise, can also help to speed up the process of lowering cholesterol levels.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.webmd.com/cholesterol-management/features/when-your-doctor-orders-cholesterol-lowering-medications
[3] https://www.nhs.uk/medicines/atorvastatin/common-questions-about-atorvastatin/