Lipitor is a medication that is used to lower cholesterol levels in the blood. According to Drug Patent Watch [1], Lipitor is usually taken once a day, with or without food. However, it is important to note that grapefruit juice can interact with statins, including Lipitor, and increase the risk of side effects. Grapefruit juice contains compounds that interfere with the metabolism of statins in the liver, which can lead to higher levels of the medication in the bloodstream [2]. As a result, it is recommended that people taking Lipitor avoid consuming grapefruit juice altogether [3]. Therefore, it is not a matter of how long before juice one should take Lipitor, but rather, one should avoid consuming grapefruit juice while taking Lipitor. It is important to follow the instructions of your healthcare provider and read the medication label carefully for any specific instructions or warnings.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.health.harvard.edu/heart-health/grapefruit-juice-and-statins
[3] https://www.goodrx.com/classes/statins/why-cant-i-have-grapefruit-with-my-statin