Lipitor is a brand name for the drug atorvastatin, which is used to lower cholesterol levels in the body. According to WebMD [2], it may take several weeks or even months to see significant results from taking Lipitor or any other cholesterol-lowering medication. The amount of time it takes to see results may depend on various factors, including the individual's overall health, the severity of their cholesterol levels, and their adherence to the medication regimen.

However, the drug patent watch [1] website indicates that the onset of action for Lipitor is relatively rapid, with a maximum effect seen within two weeks of starting treatment. It is important to note that while the maximum effect may be seen within two weeks, it may take longer for some individuals to see significant changes in their cholesterol levels.

The British Heart Foundation [3] notes that statins, including Lipitor, are generally prescribed for long-term use to help prevent heart disease and stroke. It is essential to continue taking the medication as prescribed, even if there are no immediate changes in cholesterol levels, as it can take time for the medication to have a noticeable effect.

In summary, while the onset of action for Lipitor may be relatively rapid, it may take several weeks or even months to see significant results from taking the medication. The amount of time it takes to see results may depend on various factors, including the individual's overall health, the severity of their cholesterol levels, and their adherence to the medication regimen. It is essential to continue taking the medication as prescribed, even if there are no immediate changes in 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.bhf.org.uk/informationsupport/heart-matters-magazine/medical/drug-cabinet/statins