Drug & supplement interaction

Grapefruit + Bendamustine

Bendamustine brand names: Treanda, Belrapzo, Vivimusta.

Moderate Interaction
Medically reviewed by · Updated October 2026
The bottom line Moderate

Grapefruit has a moderate interaction with Bendamustine. Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP1A2.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Grapefruit and Bendamustine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Bendamustine

Bendamustine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Grapefruit interacts with.

Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP1A2.
In vitro research suggests that grapefruit juice might inhibit CYP1A2 enzymes. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the short version: bendamustine is partly broken down by a liver enzyme called CYP1A2, and lab studies hint that grapefruit might slow that enzyme down. If that happened in your body, bendamustine could clear a little more slowly and build up, which in theory might mean stronger side effects like low blood counts, nausea, fatigue, or a higher infection risk.

The reassuring part: this is only test-tube evidence, and it has never actually been reported in people. It's a theoretical concern, not a proven one. Still, bendamustine is a serious chemotherapy drug, so it's worth a quick chat with your oncology team or pharmacist before adding regular grapefruit or grapefruit juice. Don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Grapefruit Also Interacts With Other Medications

Grapefruit has 778 major, 150 moderate, 62 minor known drug interactions in our database — the Bendamustine one above is one of them. If you take anything else, check it against the full list below.

Major 778 Moderate 150 Minor 62 No known interaction 1,840 (incl. Bendamustine)
Taking anything else?

Check Another of Your Medications Against Grapefruit

Covers the 2,830 medications we’ve checked against Grapefruit. Pick one to open its full report.

From our Q&A

Questions About Grapefruit or Bendamustine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Grapefruit or Bendamustine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Bendamustine

This page covers Grapefruit only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Bendamustine page lists 87 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Acerola (moderate), Adrafinil (moderate), African Wild Potato (moderate), Alpha-lipoic Acid (moderate) and Ashitaba (moderate).

By severity: 62 moderate · 25 minor.

From our pharmacist’s overview on the Bendamustine page

“Bendamustine (Treanda, Belrapzo, Vivimusta) is IV chemotherapy for chronic lymphocytic leukemia and certain lymphomas, and the liver clears it through an enzyme called CYP1A2. That enzyme is why nearly all 87 supplements on this page appear here, since about 80 of them can push CYP1A2 up or down, which could either raise side effects o…”

Reviewed by 2 · Jul 18, 2026

Open the Bendamustine interaction page

One more smart check

Taking Grapefruit as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,144 real supplement products containing Grapefruit, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Grapefruit. Your product may carry other ingredients that interact with Bendamustine too, on top of Grapefruit — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Grapefruit and Bendamustine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Grapefruit
Top 10%

#108 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Bendamustine
Top 5%

#121 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Grapefruit

What is Grapefruit?

Grapefruit
  • Source of vitamin C
  • Digestive complaints
  • Antimicrobial (seed extract)
  • Weight management
  • Skin and cosmetic uses

Grapefruit is a nutritious citrus fruit rich in vitamin C and other nutrients, and it is generally safe to eat. However, grapefruit is famous for serious interactions with many prescription medicines, so anyone taking medication should check with a pharmacist or doctor before consuming it regularly.

Read the full Grapefruit monograph & all interactions
Medication

About Bendamustine Injection

What Is Bendamustine Injection Used For?

Brand names: Treanda, Belrapzo, Vivimusta

Bendamustine Injection is used in adults for two blood cancers.

  • Chronic lymphocytic leukemia (CLL). How well it works compared with first-line treatments other than chlorambucil has not been established.
  • Indolent B-cell non-Hodgkin lymphoma (NHL) that has gotten worse during or within six months of treatment with rituximab or a rituximab-containing regimen.
See full Bendamustine Injection drug information
Keep checking

Other Drugs & Grapefruit

Browse every other medication we’ve checked against Grapefruit — both the ones with a known interaction and the ones without. Select any drug for the full detail.

778Major
150Moderate
62Minor
1,839No known interaction
778 Major 150 Moderate 62 Minor 1,839 No interaction
Major

778 interactions

Showing 60 of 778 major interactions — see all 778 on the Grapefruit page.

Moderate

150 interactions

Showing 60 of 150 moderate interactions — see all 150 on the Grapefruit page.

Minor

62 interactions

Showing 60 of 62 minor interactions — see all 62 on the Grapefruit page.

No interaction 1,839 drugs checked — show the list

We also checked Grapefruit against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,839 medications checked with no known interaction — see the full Grapefruit list.

See the full Grapefruit interactions page
See every supplement checked against Bendamustine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Grapefruit monograph › Uses, safety, and every drug interaction in one place Bendamustine supplement interactions › Every supplement checked against Bendamustine, ranked by severity Bendamustine Injection drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Grapefruit and Bendamustine Together: Common Questions

Can you take Grapefruit with Bendamustine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Grapefruit and Bendamustine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Bendamustine and Grapefruit?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.