Lipitor is a medication used to lower cholesterol levels in the body [1]. Grapefruit and its juice contain a compound called furanocoumarin, which can interfere with the metabolism of certain medications, including Lipitor. This interference can cause the medication to remain in the body for longer periods, leading to an increased risk of side effects [2]. Specifically, grapefruit juice can increase the concentration of Lipitor in the bloodstream, leading to a higher risk of muscle damage and liver toxicity [3]. Therefore, it is recommended to avoid consuming grapefruit or grapefruit juice while taking Lipitor to prevent potential adverse effects. Patients taking Lipitor should consult with their healthcare provider regarding any dietary restrictions or medication interactions [2].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.verywellhealth.com/can-i-take-lipitor-or-zocor-with-grapefruit-juice-1124045
[3] https://www.healthline.com/health/high-cholesterol/grapefruit-and-statins