According to the sources provided, generic Lipitor, also known as atorvastatin, is as effective as the brand-name version of the drug. Atorvastatin is a statin medication that is used to lower cholesterol levels and reduce the risk of heart attack and stroke.

The first source [1] indicates that the patent for Lipitor expired in 2011, allowing for the production of generic versions of the drug. The second source [2] states that the FDA requires generic drugs to be "bioequivalent" to the brand-name drug, meaning they must have the same active ingredient, strength, dosage form, and route of administration.

The third source [3] explains that generic drugs are required to undergo rigorous testing to ensure their safety and effectiveness. In fact, the FDA requires that generic drugs be tested in humans to demonstrate that they are bioequivalent to the brand-name drug.

Furthermore, the second source [2] cites a study that found no significant differences in cholesterol-lowering effectiveness between Lipitor and generic atorvastatin. The study also found no significant differences in side effects between the two drugs.

In conclusion, based on the sources provided, generic Lipitor (atorvastatin) is as effective as the brand-name version of the drug. The FDA requires that generic drugs be bioequivalent to their brand-name counterparts, and studies have shown no significant differences in effectiveness or side effects between Lipitor and generic atorvastatin.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.health.harvard.edu/blog/switching-to-generic-lipitor-201202064195
[3] https://ro.co/health-guide/generic-lipitor/