A freshly squeezed glass of grapefruit juice can be a healthy way to jumpstart your day. But if you're taking medicines along with your breakfast, you may want to forgo that bittersweet grapefruit juice and opt for OJ instead.
As it turns out, grapefruit juice contains an organic chemical known as furanocoumarin. This chemical can interfere with the activity of enzymes and transporters in the small intestine that metabolize your medications. Washing down pills with grapefruit juice can cause your body to absorb too much or too little of certain medicines, potentially causing serious problems.
The FDA currently lists more than 50 prescription and over-the-counter drugs that have negative interactions with grapefruit. Common drugs on this list include medicines for high cholesterol, high blood pressure, and anxiety. So check the labels on your pill bottles for grapefruit contraindications. When in doubt, water, though not so tasty, is a safe option.