Lipitor is a medication used to lower cholesterol levels in the blood, which can help prevent heart attacks, strokes, and other cardiovascular diseases. According to the drug patent watch website [1], Lipitor's active ingredient is atorvastatin calcium, which inhibits the enzyme HMG-CoA reductase, an enzyme that plays a crucial role in the production of cholesterol in the liver. By inhibiting this enzyme, Lipitor reduces the amount of cholesterol produced in the liver, which, in turn, lowers the total cholesterol levels in the blood.

WebMD [2] states that Lipitor is typically prescribed along with a low-fat diet to help reduce cholesterol levels. A low-fat diet is a diet that restricts the intake of fat, especially saturated and trans fats, which are known to raise cholesterol levels in the blood. By reducing the intake of these fats, the liver produces less cholesterol, which can help lower total cholesterol levels in the blood.

A study published in the National Library of Medicine [3] found that combining a low-fat diet with atorvastatin (Lipitor) resulted in a significant reduction in total cholesterol levels, LDL cholesterol (the "bad" cholesterol), and triglycerides. The study also found that atorvastatin was more effective in reducing cholesterol levels when combined with a low-fat diet than when used alone.

In conclusion, Lipitor works by inhibiting the production of cholesterol in the liver, and it is typically prescribed along with a low-fat diet to help reduce cholesterol levels in the blood. A low-fat diet can help reduce the amount of cholesterol produced in the liver, which can enhance the effectiveness of Lipitor in reducing cholesterol levels.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.webmd.com/drugs/2/drug-3330/lipitor-oral/details
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1312230/