Caution
Grapefruit contains high levels of flavonoid naringin that will reject synthetic man-made drugs. This is beneficial for our human cells because it helps to recognize alien compounds which should not be in our body, therefore, are treated as toxins.
The presence of grapefruits may halt the metabolism of these drugs, leaving the drugs in your body thus creating the risk of toxic poisoning. Doctors may tell you that grapefruit is the cause of the toxicity, but in fact, it is really the drugs that is causing the toxicity.
If you are not under medication, grapefruit juice can do a world of good. However, despite all its goodness, always remember to take only in moderation. Excessive consumption of any citrus juices can leach calcium from the body system, causing decay of the bones and teeth.