Administration of grapefruit juice in humans results in a decrease in the level of CYP3A in the intestine,2 an important site
for metabolism
for many medications. This mechanism would account for the increase in levels of medications that are metabolized by CYP3A when concomitantly administered with grapefruit juice.
A list of medications that have been shown, in clinical studies, to have an interaction with grapefruit juice can be found in the table below.