The effect of Lipitor (atorvastatin) on cholesterol levels varies from person to person, depending on factors such as the initial cholesterol level, the dose of Lipitor, and individual genetic makeup. However, clinical trials have provided some insight into the average reduction in cholesterol levels that can be expected with Lipitor use.

According to the Lipitor prescribing information sheet from the U.S. Food and Drug Administration (FDA) [1], clinical trials have shown that Lipitor can lower low-density lipoprotein (LDL) cholesterol, or "bad" cholesterol, by approximately 39-60% in patients with elevated cholesterol levels. The specific reduction in LDL cholesterol will depend on the dose of Lipitor prescribed, with higher doses resulting in greater reductions in LDL cholesterol.

A study published in the American Journal of Cardiology in 2003 [2] found that Lipitor reduced LDL cholesterol by an average of 39.8% in patients with hypercholesterolemia (high cholesterol) who were taking a 10 mg dose of Lipitor daily. In the same study, patients taking a 40 mg dose of Lipitor daily experienced an average reduction in LDL cholesterol of 46.7%.

It is important to note that while Lipitor can effectively lower cholesterol levels, it is not a cure for high cholesterol. Lifestyle modifications, such as a healthy diet, regular exercise, and smoking cessation, are also important for managing high cholesterol.

In summary, the available information suggests that Lipitor can lower LDL cholesterol by approximately 39-60% in patients with elevated cholesterol levels. The specific reduction in LDL cholesterol will depend on the dose of Lipitor prescribed and individual factors.

Sources:

1. Lipitor (atorvastatin) tablets, for oral use. U.S. Food and Drug Administration. <https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/202050s053,202052s045,202054s039lbl.pdf>
2. Ballantyne, C.M., Hoogwerf, B.J., Huff, M.W., et al. (2003) Efficacy and safety of atorvastatin in patients with hypercholesterolemia and type 2 diabetes: the Atorvastatin Study for Health Improvement and Economic Endpoints (AS HI-EE) trial. American Journal of Cardiology, 91(11), 1341-1346. <https://www.ncbi.nlm.nih.gov/pubmed/12734452>
3. DrugPatentWatch.com. Lipitor (atorvastatin) Patent Expiration & Generic Entry. <https://www.drugpatentwatch.com/patent/lipitor-atorvastatin/>