According to the sources provided, generic Lipitor, also known as atorvastatin, is generally considered to be as effective as the brand-name version of the drug.

The first source, Drug Patent Watch, provides information on the patent status of various drugs, including Lipitor. It confirms that the patent for Lipitor expired in 2011, which allowed for the production of generic versions of the drug. This suggests that generic Lipitor contains the same active ingredient as the brand-name version.

The second source, a study published in the National Center for Biotechnology Information, evaluates the bioequivalence of generic atorvastatin compared to the brand-name Lipitor. The study concludes that generic atorvastatin is bioequivalent to Lipitor, meaning it has the same rate and extent of absorption in the body. This indicates that generic atorvastatin is expected to have the same therapeutic effect as the brand-name version.

The third source, an article from Harvard Health Publishing, discusses the switch from brand-name Lipitor to generic atorvastatin. It states that the U.S. Food and Drug Administration (FDA) requires generic drugs to be equivalent to their brand-name counterparts in terms of quality, strength, purity, and stability. The article further emphasizes that generic drugs undergo rigorous testing to ensure their safety and effectiveness.

In conclusion, based on the provided sources, it can be inferred that generic Lipitor, or atorvastatin, is generally considered to be as effective as the brand-name version of the drug. The expiration of the Lipitor patent and the bioequivalence studies suggest that generic atorvastatin has the same therapeutic effect as the brand-name version. It is important to consult with a healthcare professional to determine the most appropriate medication for individual circumstances.

Sources:
[1] Drug Patent Watch: https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] National Center for Biotechnology Information: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4859299/
[3] Harvard Health Publishing: https://www.health.harvard.edu/blog/switching-to-generic-lipitor-201202064195