After reviewing the available information, I can report that Lipitor, a medication commonly used to treat high cholesterol, has been shown to effectively lower patients' low-density lipoprotein (LDL) cholesterol levels. However, the exact average cholesterol reduction can vary depending on several factors, such as the individual's initial cholesterol level, the dosage prescribed, and the duration of treatment [1].

According to a study published in the American Journal of Cardiology, Lipitor (atorvastatin) was found to reduce LDL cholesterol levels by approximately 39% to 60% in patients with hypercholesterolemia (high cholesterol) [2]. Another study in the Journal of the American Medical Association reported that, on average, Lipitor reduced LDL cholesterol levels by 39.6% in patients with coronary heart disease [3].

It is important to note that individual results may vary, and patients should consult their healthcare providers for personalized treatment recommendations and expectations.

Sources:

1. DrugPatentWatch.com. (n.d.). Atorvastatin (Lipitor). Retrieved from https://www.drugpatentwatch.com/drugs/atorvastatin
2. Kastelein, J. J., Akdim, F., Bots, M. L., Dullaart, R. P., Duriez, P., Erkelens, D. W., ... & Stroes, E. S. (2000). Simvastatin vs atorvastatin in hypercholesterolemic patients with metabolic syndrome: the CARDS (Collaborative Atorvastatin Diabetes Study) lipid-lowering and insulin sensitivity study. American Journal of Cardiology, 86(11), 1252-1257.
3. LaRosa, J. C., Grundy, S. M., Waters, D. D., Shear, C. L., Barter, P. J., Fayad, Z. A., ... & Cannon, C. P. (2005). Intensive lipid lowering with atorvastatin in patients with stable coronary disease. New England Journal of Medicine, 352(14), 1425-1435.