Lipitor is a medication used to lower cholesterol levels in the body [1]. Grapefruit contains a compound that inhibits an enzyme in the body responsible for breaking down certain medications, including Lipitor. This can lead to an increase in the amount of Lipitor in the body, which may increase the risk of side effects [2][3]. Therefore, it is recommended to avoid consuming grapefruit or grapefruit juice while taking Lipitor. Patients should always consult with their healthcare provider before making any changes to their medication regimen or diet [2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/classes/statins/why-cant-i-have-grapefruit-with-my-statin
[3] https://www.nhs.uk/common-health-questions/medicines/does-grapefruit-affect-my-medicine/