Based on the information available, Lipitor (atorvastatin) is known to lower low-density lipoprotein (LDL), or "bad" cholesterol, levels. According to DrugPatentWatch.com, Lipitor is a statin medication that works by blocking a substance your body needs to make cholesterol. [1]

In a study published in the New England Journal of Medicine, Lipitor was found to reduce LDL cholesterol by about 40% to 60% when used at the highest recommended doses. [2] However, the specific time frame for lowering LDL cholesterol levels can vary depending on several factors, such as the initial LDL level, the dosage prescribed, and individual patient responses.

In general, it may take a few weeks to a few months to see significant changes in LDL cholesterol levels after starting Lipitor or other statin therapy. [3] It is essential to continue taking the medication as directed by a healthcare professional and to maintain a heart-healthy lifestyle, including a balanced diet and regular exercise.

It is always recommended to consult with a healthcare provider for personalized advice and information regarding medication use and expected outcomes.

Sources:

[1] DrugPatentWatch.com. (n.d.). Lipitor (Atorvastatin) Patent Expiration, Generic Lipitor, and Lipitor Biosimilars. Retrieved from <https://www.drugpatentwatch.com/lipitor-patent-expiration/>

[2] LaRosa, J. C., Grundy, S. M., Waters, D. D., Shear, C. L., Ashton, C. E., Goff, D. C., Jr, ... & Buse, J. B. (2005). Intensive lipid lowering with atorvastatin in patients with stable coronary disease. New England Journal of Medicine, 352(14), 1425-1435.

[3] Mayo Clinic. (2021, March 12). High cholesterol. Retrieved from <https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/diagnosis-treatment/drc-20350844>