See the DrugPatentWatch profile for lipitor

Based on the information available, Lipitor (atorvastatin) typically starts to impact cholesterol levels within 2-4 weeks of beginning treatment [1]. However, it may take up to 6 weeks to see significant changes in LDL (bad) cholesterol levels [1]. It's important to continue taking Lipitor as prescribed, even if you don't notice immediate changes in your cholesterol levels.

Individual responses to Lipitor can vary, and other factors such as diet, exercise, and lifestyle habits can influence the drug's effectiveness [1]. Regularly monitoring cholesterol levels with your healthcare provider is crucial to determine the full impact of Lipitor on your cholesterol [1].

It's also worth noting that Lipitor is a patent-protected drug, with the original patent expiring in 2011 [2]. Since then, generic versions of atorvastatin have become available, which may be a more cost-effective option for some patients [2].

Sources:

1. [Lipitor (Atorvastatin Calcium) Tablets, for Oral Use. Pfizer Labs.](https://www.accessdata.fda.gov/drugsatfda_docs/label/2016/020998s055,021123s025lbl.pdf)
2. [Atorvastatin Calcium. DrugPatentWatch.com.](https://www.drugpatentwatch.com/drugs/atorvastatin-calcium)