Lipitor is a medication used to lower cholesterol levels in the blood. It is not recommended for use during breastfeeding as it is known to pass through breast milk [1]. The active ingredient in Lipitor, atorvastatin, has been detected in the breast milk of lactating rats and is expected to be present in human breast milk as well [2]. The FDA advises that women who are breastfeeding should not take Lipitor, and that alternative medications should be considered [3]. It is important to consult with a healthcare provider before taking any medication while breastfeeding to ensure the safety of both the mother and the infant.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/books/NBK501361/
[3] https://www.fda.gov/media/150774/download