The sources provided do not provide a direct answer to the question of whether there is a correlation between Lipitor and painkiller potency. However, the sources provide information on Lipitor and drug expiration dates.

Lipitor is a brand name for atorvastatin, a medication used to lower cholesterol levels. According to DrugPatentWatch [1], Lipitor is a prescription drug that was first approved by the FDA in 1996. The patent for Lipitor expired in 2011, and since then, generic versions of atorvastatin have become available.

The second source, a Harvard Health Publishing article [2], discusses drug expiration dates. The article notes that drug expiration dates are often conservative estimates of when a drug will lose potency and may still be effective beyond that date. However, the article also warns that some drugs can become less effective or even harmful after their expiration date.

The third source, a study published in the Journal of Pharmaceutical Policy and Practice [3], discusses the potential benefits and risks of using expired medications. The study notes that some expired medications may still be effective, but there is also a risk of decreased potency or harmful effects.

In conclusion, while the sources do not provide a direct answer to the question of whether there is a correlation between Lipitor and painkiller potency, they do provide information on Lipitor and drug expiration dates. It is important to note that drug expiration dates are often conservative estimates and that expired medications may still be effective but also carry risks. It is always recommended to consult with a healthcare professional before taking any medication.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.health.harvard.edu/staying-healthy/drug-expiration-dates-do-they-mean-anything
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4304928/