Lipitor is a brand name for the drug atorvastatin, which is a medication used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], the patent for Lipitor expired in 2011, which means that generic versions of atorvastatin are now available.

The potency and duration of Lipitor have been studied in various clinical trials. A study published in the Journal of Clinical Lipidology [2] found that atorvastatin had a dose-dependent effect on reducing LDL cholesterol levels, with higher doses resulting in greater reductions. The study also found that the effects of atorvastatin on LDL cholesterol levels were sustained over a 52-week period.

Another study published in the journal Pharmacology [3] found that atorvastatin had a half-life of approximately 14 hours in the body. This means that it takes approximately 14 hours for half of the drug to be eliminated from the body. The study also found that atorvastatin was highly effective at reducing LDL cholesterol levels, with significant reductions observed within two weeks of starting treatment.

In summary, Lipitor (atorvastatin) is a medication used to lower cholesterol levels in the blood. The potency of atorvastatin is dose-dependent, with higher doses resulting in greater reductions in LDL cholesterol levels. The effects of atorvastatin on LDL cholesterol levels are sustained over a 52-week period. Atorvastatin has a half-life of approximately 14 hours in the body and is highly effective at reducing LDL cholesterol levels within two weeks of starting treatment.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4799528/
[3] https://pubmed.ncbi.nlm.nih.gov/23511950/