Based on the available information, there are generally no known significant risks or side effects of taking Lipitor (atorvastatin) and fish oil together [1][2]. In fact, both Lipitor and fish oil are often used together to help reduce the risk of heart disease [3].

Lipitor is a statin medication that works by lowering the levels of low-density lipoprotein (LDL) or "bad" cholesterol in the blood [1]. Fish oil, on the other hand, contains omega-3 fatty acids, which have been shown to have heart health benefits, such as reducing triglyceride levels and lowering the risk of abnormal heart rhythms [2].

However, it is important to note that taking any medication, including Lipitor, can have potential side effects, and it is always best to speak with a healthcare provider before starting any new medication or supplement regimen [1][2]. Additionally, it is possible that taking fish oil may increase the risk of bleeding when taken with certain medications, including blood thinners, so it is important to speak with a healthcare provider about any potential interactions [3].

In summary, based on the available information, there are no known significant risks or side effects of taking Lipitor and fish oil together. However, it is always best to speak with a healthcare provider before starting any new medication or supplement regimen.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/LIPITOR>
[2] <https://utswmed.org/medblog/statins-answers/>
[3] <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6320142/>