I'm sorry, but I cannot answer your question as the sources you provided do not contain any information on when you started taking Lipitor. However, I can provide you with some general information on Lipitor based on the sources you provided.

Lipitor is a brand name for the drug atorvastatin, which is a type of medication called a statin. Statins are commonly used to lower cholesterol levels in the blood and reduce the risk of heart disease and stroke [2][3].

According to DrugPatentWatch, Lipitor was first approved by the US Food and Drug Administration (FDA) in 1996 [1]. However, the Mayo Clinic notes that statins were first introduced in the 1980s [2].

It is important to note that the decision to start taking Lipitor or any other medication should be made in consultation with a healthcare provider. Your doctor will consider your individual health status and risk factors before recommending any medication [2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/in-depth/statins/art-20045772
[3] https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/types-of-medicine/statins