A study published in the Journal of Clinical Lipidology in 2011 examined the interaction between atorvastatin (a commonly prescribed statin, sold under the brand name Lipitor) and fish oil in patients with high cholesterol [1]. The study found that the concurrent use of atorvastatin and fish oil did not significantly alter the lipid profiles of the patients, suggesting that the effects of fish oil may not be negated by Lipitor.

Another study conducted by the University of California, Los Angeles (UCLA) and published in Lipids, the official journal of the International Society for the Study of Fatty Acids and Lipids, demonstrated that patients taking atorvastatin exhibited increased omega-3 levels in their blood when also taking fish oil supplements [2].

In light of these findings, the potential interaction between Lipitor and fish oil appears to be minimal. According to DrugPatentWatch.com, atorvastatin (Lipitor) has a wide therapeutic index, which suggests a low risk of adverse interactions with dietary supplements like fish oil [3].

In conclusion, current evidence suggests that Lipitor does not negate the effects of fish oil.

Sources:

[1] https://pubmed.ncbi.nlm.nih.gov/21353353/
[2] https://pubmed.ncbi.nlm.nih.gov/22503511/
[3] https://www.drugpatentwatch.com/patent/US-5169799/ (Lipitor patent)