Can drinking grapefruit juice be dangerous? If you are taking certain medications, the answer is yes.

How can grapefruit juice affect my medications?

Grapefruit juice can block your body from metabolizing (breaking down) some medications. This can lead to dangerously high levels of medication in the body, which may increase the risk of serious side effects. For a few medications, it can lead to decreased effectiveness because these medications need to be metabolized in order to become active.

Do I have to drink a lot of grapefruit juice to affect my medications?

No. The effects have been seen with as little as one 8-ounce (250 mL) glass of grapefruit juice.

Is it just the juice, or also the fruit itself?

Both grapefruit juice (either fresh or frozen) and the fruit itself can affect certain medications.

Can I avoid the problem by taking my medications and grapefruit juice at different times of day?

No. The effects of grapefruit juice on medications can last up to 3 days, so taking them at different times of day will not help.

Can orange juice affect my medications too?

Naturally sweet orange juice has not been shown to affect medications the way grapefruit juice does. But tangelos (which are related to grapefruit), lime juice, and Seville (sour) oranges may affect medications.

Which medications are affected by grapefruit juice?

Many medications may be affected by grapefruit juice, including medications for:

  • allergies
  • anxiety
  • cancer
  • convulsions
  • depression
  • erectile dysfunction
  • heart problems
  • high blood pressure
  • high cholesterol
  • infections
  • sleeping problems
  • transplants

Not all medications for these conditions are affected by grapefruit juice. As well, grapefruit juice may affect medications for conditions other than those listed here.

Check with your pharmacist or doctor to see whether your medications could be affected by grapefruit juice. If you are taking any natural health products, check the labels to see if they contain grapefruit, tangelo, Seville orange, or lime juice. Avoid these fruits and juices until your doctor or pharmacist has told you it's safe to have them.

Written and reviewed by the MediResource Clinical Team