Aspirin and Lipitor are two different medications that are used to treat different conditions. Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that is used to relieve pain, reduce inflammation, and prevent blood clots. Lipitor is a statin medication that is used to lower cholesterol levels in the blood.

There is no evidence to suggest that aspirin affects the effectiveness of Lipitor. However, it is important to note that both medications can have side effects and may interact with other medications.

A study published in the Journal of Experimental & Clinical Cancer Research [2] investigated the effects of aspirin on the growth of cancer cells. The study found that aspirin can inhibit the growth of cancer cells and enhance the effectiveness of chemotherapy. However, this study did not investigate the effects of aspirin on the effectiveness of Lipitor.

Another study published in the Journal of Clinical Pharmacology [3] investigated the potential interactions between aspirin and statins. The study found that aspirin does not affect the pharmacokinetics of statins, including Lipitor. However, the study did note that both aspirin and statins can increase the risk of bleeding, and caution should be taken when using these medications together.

In summary, there is no evidence to suggest that aspirin affects the effectiveness of Lipitor. However, both medications can have side effects and may interact with other medications. It is important to speak with a healthcare provider before taking any new medications or making changes to an existing medication regimen.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ASPIRIN
[2] https://jeccr.biomedcentral.com/articles/10.1186/s13046-016-0304-4
[3] https://pubmed.ncbi.nlm.nih.gov/16520473/