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Mixing grapefruit and medications may not seem like a big concern, but it can be if you take certain prescription or over-the-counter drugs.
Understanding these interactions can help you manage your medications. It can also help avoid unwanted side effects.
“For most people, a normal amount of grapefruit will produce a very large difference in drug exposure,” said Gail Clifford, MD, medical consultant of Paramount Wellness Retreat in Haddam, Connecticut.
This guide:
- Explains why grapefruit drug interactions happen
- Defines what specific kinds of medications may be affected and the potential risks
- Addresses some common questions about grapefruit juice and medications
Grapefruit and its juice do not interact with every medication. Even when they do, the effects can vary depending on the specific drug and the person taking it. Understanding more about grapefruit and medications can help you know when to avoid combining them.
Medications That Can Interact with Grapefruit at a Glance
| Cholesterol-lowing medications | simvastatin, atorvastatin, and lovastatin may have severe interactions; rosuvastatin and pravastatin have a lower interaction risk |
| Blood presssure and heart medications | calcium channel blockers are ones to watch |
| Allergy medications | chance of interaction varies by medication |
| Anxiety and mental health medications | medications to treat anxiety, depression, or other mental health conditions may interact with grapefruit |
| Organ transplant medications | cyclosporine, tacrolimus, and some other organ transplant medications interact with grapefruit |
Why does grapefruit interact with medications?
Grapefruit interacts with some medications because of compounds in the fruit. These can change how certain drugs are absorbed or broken down in the body. Usually, enzymes in your gut break down medications before they enter your bloodstream. This includes the enzyme CYP3A4. But the compounds in grapefruit can block CYP3A4 so it doesn’t do its job. This can cause more of the medication to enter the bloodstream than intended. Grapefruit compounds can also affect proteins with the opposite effect. This can prevent enough of a drug from entering the bloodstream.
“Grapefruit either increases how much of a drug gets absorbed and therefore into circulation, or decreases absorption through interference with transport proteins,” said Julia Loewenthal, MD, assistant professor at Harvard Medical School in Boston, Massachusetts, and primary care physician and geriatrician at Lutanen Health. “Either too little of the drug works or it doesn’t work at all, or there are toxic side effects. And sometimes both happen.”
What medications interact with grapefruit?
“Certain medications, including blood-pressure and heart medications, transplant drugs, statins, and a few medications prescribed for depression or anxiety, will interact with grapefruit,” said Louis Lerebours, MD, family medicine physician at Freeman Recovery Center in Nashville, Tennessee. “Some allergy or prescription medications that are used to treat allergies or other medical conditions may also be affected.”
Some medications come with a grapefruit warning in their instructions. Reading these instructions closely is important. Not every medication will interact with grapefruit and the following list is not comprehensive. You should check with your health care provider about any specific medication you take.
| Common Types of Medications Known to Interact with Grapefruit |
| Cholesterol-lowering medications Statins are common cholesterol-lowering drugs. Not all statins have the same grapefruit risk. “Statins are some of the most widely known examples, though it’s not all statins that interact with grapefruit in the same way,” said Dr. Loewenthal. “Simvastatin, atorvastatin, and lovastatin may lead to more severe interactions, while ones like rosuvastatin and pravastatin have a lower risk.” Grapefruit can raise the amount of some statins in the blood. This may increase the risk of serious muscle problems or liver damage. |
| Blood pressure and heart medications Grapefruit can also affect medicines used for high blood pressure and other heart conditions. Calcium channel blockers are one group to watch. “Some blood pressure and heart medications, especially calcium channel blockers, may also interact,” said Dr. Loewenthal. |
| Organ transplant medications People who have had an organ transplant may take medicines called immunosuppressants. These help prevent organ rejection. Some of these drugs, including cyclosporine and tacrolimus, can interact with grapefruit. “Cyclosporine, tacrolimus, and some other organ transplant medications interact with grapefruit, and this can be especially concerning since stable dosing of these medications is critical,” said Dr. Loewenthal. Always talk with your doctor or pharmacist before consuming grapefruit or grapefruit juice while taking these medications. |
| Anxiety and mental health medications Certain medicines used for anxiety, depression, or other mental health conditions may also have grapefruit contraindications. The risk varies by the drug. Don’t assume that every medication in one group will interact with grapefruit. Your doctor or pharmacist can tell you whether your specific medicine is affected. |
| Allergy medications Some allergy medicines can have grapefruit and drug interactions, too. But interactions vary by medication. “That’s why I always tell patients to check with a doctor or pharmacist about a specific interaction,” said Dr. Loewenthal. |
Grapefruit does not always increase the amount of a medicine in your blood. In some cases, it can reduce how much of a drug your body absorbs. “Grapefruit products can lower plasma concentrations of other drugs, including the antihistamine fexofenadine,” said Dr. Clifford. This drug is sold over the counter under the brand name Allegra.
What can happen if grapefruit interacts with medication?
What happens when grapefruit interacts with medication depends on several factors. The specific drug, amount of grapefruit, and how your body responds all play a role. Grapefruit can cause some medicines to reach higher levels in the blood. This may increase side effects or the risk of toxicity.
In other cases, grapefruit juice and medications can interact in a way that lowers the amount of medicine your body absorbs. This can make the drug less effective.
The effects of grapefruit drug interactions can range from mild to serious.
“Some medications have adverse reactions as a result of levels going too high. One example is the cholesterol medication simvastatin. When this statin interacts with grapefruit, it can cause large amounts to build up in the blood, which can lead to muscle injury and kidney and liver damage,” said Dorothy Ogwuru, MD, founder of PharmaLink Academy in the United Kingdom and a pharmaceutical industry professional. “A lot of people don’t realize that if they experience unexplained muscle pain, tenderness or weakness while taking a statin, they should immediately see a doctor.”
Here are some of the other possible symptoms of a grapefruit and medication interaction:
- Low blood pressure
- Feeling faint
- Irregular or rapid heartbeat
- Dizziness
- Extreme daytime sleepiness
- Frequent kidney infections
What symptoms may signal a serious drug interaction?
Warning signs can vary depending on the medication, but some symptoms should not be ignored.
“Warning signs vary depending on the drug, but may also include very bad dizziness or fainting, an abnormally rapid or abnormal heartbeat, significant muscle pain or weakness, confusion, or other serious or unusual symptoms,” said Dr. Lerebours. “A health care provider should be contacted immediately to discuss new or concerning symptoms that occur when grapefruit is taken in conjunction with drugs.”
Contact your health care provider if you develop new or unusual symptoms after eating grapefruit or drinking grapefruit juice.
How much grapefruit can cause a drug interaction?
“There is no known safe amount of grapefruit for all medications. It depends on the patient, the drug, and the strength and type of the grapefruit product,” said Dr. Ogwuru.
“The FDA states that grapefruit juice products can range in strength from a moderate inhibitor to a strong one for CYP3A.”2 In other words, grapefruit juice can affect this drug-processing enzyme to different degrees. If you take a medication with a grapefruit warning, don’t try to find your own safe serving size. Ask your pharmacist or health care provider about grapefruit and medications.
Can you separate grapefruit and medication by a few hours?
Taking medication a few hours after eating grapefruit may not prevent an interaction. “Even one glass of grapefruit juice or a single grapefruit can make some medications more potent. And unfortunately, spacing it out doesn’t help because the enzyme that grapefruit blocks can take up to three days to recover,” said Dr. Loewenthal.3
If you accidentally eat grapefruit or drink grapefruit juice while taking a medication with a grapefruit warning, don’t skip or change your dose on your own. “My practical advice: Check the medication information, medication guides or OTC drug facts, and ask your pharmacist or the prescribing clinician whether your specific medication interacts with grapefruit,” said Dr. Ogwuru. “If you happen to eat grapefruit when you shouldn’t because you are taking a medication that interacts with grapefruit, do not independently change your medication. Contact your pharmacist or health care provider first.”
What other fruits can interact with medications?
Grapefruit is not the only fruit that can cause a drug interaction. Other fruits contain some of the same compounds found in grapefruit and may affect certain medications. “Seville oranges, pomelos, and tangelos contain similar compounds and present similar risks. If in doubt, ask your health care provider or pharmacist.” said Dr. Loewenthal.
It’s also important to think about any foods you eat that may contain these as ingredients. Seville oranges, for example, are often used to make marmalade. So having marmalade on toast could potentially cause an interaction with medication. “Like grapefruit juice, orange juice as well as apple juice can cause a similar effect,” said Dr. Ogwuru.4 The effects can depend on the specific drug you take. Check with your pharmacist or health care provider if you’re unsure which fruits or juices are safe with your medication.
How can you tell if your medication interacts with grapefruit?
The best way to find out what medications interact with grapefruit is to check your medication guide. You can also ask your pharmacist or health care provider. Look for a warning about grapefruit, grapefruit juice, or other citrus products.
“The most reliable way to know if a medication is interacting with grapefruit is to ask your health care provider or pharmacist,” said Dr. Loewenthal. “They can also answer questions about if you should skip your medication. But this isn’t always the best option since skipping a dose carries its own risks.”
You can also check the drug facts or prescribing information for your medication. Always ask If you’re unsure about whether grapefruit juice and your medications can be used together.
Frequently asked questions
Does grapefruit juice interact with medications differently than grapefruit?
Both grapefruit and grapefruit juice can interact with certain medications. The strength of the effect can vary based on the amount and type of grapefruit product.
Should you stop taking medication if you ate grapefruit?
No, do not stop or change your medication on your own if you accidentally ate grapefruit. Contact your pharmacist or health care provider about what you should do.
Does grapefruit interact with blood pressure medication?
Yes, grapefruit can interact with some blood pressure medicines. It has been known to interact with certain calcium channel blockers. Not every blood pressure medication is affected, so check with your pharmacist or health care provider.
What should you do if you accidentally eat grapefruit with medication?
Don’t skip your next dose or change your medication without advice from your health care provider. Contact your pharmacist or prescriber and tell them which medication you take and how much grapefruit you ate.
How long after eating grapefruit should I wait before taking medication?
The effects of eating grapefruit can last anywhere from 24 hours to three days. When in doubt, ask your doctor.
Sources
1. Innes, G., et al. Prescription medication use among older adults in the US. JAMA Internal Medicine. July 1, 2024. Found on the internet at: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2820722
2. U.S. Food & Drug Administration. Grapefruit Juice and Some Drugs Don't Mix. July 7, 2021. Found on the internet at: https://www.fda.gov/consumers/consumer-updates/grapefruit-juice-and-some-drugs-dont-mix
3. Kiani, J., et al. Medicinal importance of grapefruit juice and its interaction with various drugs. Nutrition Journal. Oct. 30, 2007. Found on the internet at: https://link.springer.com/article/10.1186/1475-2891-6-33
4. Petric, Z., et al. Food-Drug Interactions with Fruit Juices. Foods. Dec 24, 2020. Found on the internet at: https://www.mdpi.com/2304-8158/10/1/33
