Clinical Cancer Research: A study funded by the US National Institute of Health indicates that people with cancer might be able to take less of a chemotherapy drug if they take it with grapefruit juice.
Apparently grapefruit juice interacts with some types of medications – very often with adverse effects which can contribute to overdosing hazards.
Combining sirolimus with grapefruit juice causes blood levels of the drug to rise to potentially effective levels with relatively few side-effects.
Different types of grapefruit seem to vary the potency and effectiveness, depending on the the levels of furanocoumarin in the grapefruit. Interesting!