Grapefruit

Studies in people

• Open question

  Drug absorption in the body²

  Grapefruit can raise how much of some medicines the body absorbs, even from one glass.

• Open question

  Medicine strength in the body³

  A glass of grapefruit juice can raise how much of some drugs the body takes in.

Animal and lab studies only

• Open question

  Medicine absorption in the gut⁷

  In lab studies, some grapefruit compounds blocked a gut protein that takes in estrone 3-sulfate.

• Open question

  Vitamin A from food⁸

  In lab studies, grapefruit juice lowered how much beta-carotene could be taken from boiled sweet potato by up to 30%.

Study type not stated

• Open question

  Medicine interactions⁶

  Grapefruit can change how the body handles some medicines, affecting how they are broken down or passed out.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Heart rhythm risk⁴

  Drinking grapefruit juice can raise the amount of some medicines in your blood, which may disturb your heart rate.

How it’s made and used

• Urinary excretion of bergaptol⁵

  In people, drinking grapefruit juice led to bergaptol in urine, and other furocoumarins seemed changed into it.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.