Grapefruit can have negative interactions with some medications. Here's what's going on in your body. 


How can a fruit as innocuous as grapefruit possibly cause problems with medications, you may wonder. 

Turns out it’s not a falsity, grapefruit, and grapefruit juice, can turn some common medications into a hazard for your health. (And it all begins with a word that I surely can’t pronounce, but you should have fun trying to - furanocoumarins.)

Yes, grapefruit can be a healthy diet choice. It’s chock-full of vitamin C and potassium. But, it may have some unwanted side effects on your medications. This juice, in particular, can increase the active amount of certain drugs that enter your bloodstream, increasing the risk of potential pesky side effects. 

Possible Drug Interactions

Too much of any medicine can cause unwanted side effects. Let’s see how this interaction happens in the first place.

The body produces an enzyme in the small intestine that helps break down medications. Grapefruit juice (and its furanocoumarins) can effectively stop this enzyme from doing its job properly. The unintended results are a larger amount of the medication in the bloodstream - that stays there, active, for a longer period of time. 

There can be an opposite effect as well. Grapefruit juice can affect drug transporters (proteins) in the body. This means less of the drug gets to where it belongs for the body to use. 

According to Harvard Health Publishing, “It doesn't take much grapefruit juice to boost the levels of drugs that are susceptible. A single glass can produce a 47% reduction of the intestinal enzyme that regulates absorption. And because this effect of the juice wears off slowly, a third of its impact is still evident after 24 hours.”

Medication List

According to the U.S. Food and Drug Administration (FDA), there are quite a few prescription and over-the-counter medications that carry warnings to avoid grapefruit, including some that may be commonly used by people with diabetes.

For a list of drugs that interact with grapefruit, please see this list from Drugs.com to get started.

How to Be Mindful With Your Medications

  • Have a complete and current list of your medications

  • Talk with your health care provider and your pharmacist

  • Ask about possible food/drug interactions

  • Determine if any of your medications, not just your diabetes medications, have a suggested list of things to avoid