Lipitor, also known as atorvastatin, is a medication used to treat high cholesterol levels. According to the sources provided, Lipitor has been effective in lowering cholesterol levels in patients.

One source [3] explains that statins, such as Lipitor, work by blocking a substance the liver needs to produce cholesterol, which in turn causes the liver to remove cholesterol from the blood. This results in a decrease in LDL (bad) cholesterol levels and an increase in HDL (good) cholesterol levels.

Another source [2] states that Lipitor has been shown to lower LDL cholesterol levels by 39-60%, depending on the dosage and individual response. It also notes that Lipitor can reduce the risk of heart attack, stroke, and other cardiovascular events in patients with high cholesterol levels.

A third source [1] provides data on the effectiveness of Lipitor in lowering cholesterol levels. It states that in clinical trials, Lipitor was shown to reduce LDL cholesterol levels by an average of 29-45% in patients with hyperlipidemia (high cholesterol levels).

In summary, based on the sources provided, Lipitor has been effective in lowering cholesterol levels in patients. It works by blocking the liver's production of cholesterol, resulting in a decrease in LDL cholesterol levels and an increase in HDL cholesterol levels. Clinical trials have shown that Lipitor can reduce LDL cholesterol levels by an average of 29-60%, depending on the dosage and individual response. Lipitor can also reduce the risk of cardiovascular events in patients with high cholesterol levels.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.medicalnewstoday.com/articles/248136
[3] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statins/art-20045772