Drug & supplement interaction

Grape + Polatuzumab Vedotin-Piiq

Polatuzumab Vedotin-Piiq brand name: Polivy.

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

Grape has a moderate interaction with Polatuzumab Vedotin-Piiq. It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Grape and Polatuzumab Vedotin-Piiq

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Polatuzumab Vedotin-Piiq

Polatuzumab Vedotin-Piiq falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Grape interacts with.

It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.
In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes. However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver. So far, these interactions have 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 honest picture with Polivy and grape seed extract. The active cancer-killing piece of this drug (a payload called MMAE) is partly handled by a liver enzyme known as CYP3A4. Grape seed extract might nudge that enzyme, but the research is genuinely mixed: lab dish studies hint it could slow the enzyme down, while animal studies suggest it could speed it up. Nobody has actually seen this play out in people.

Because the direction is unclear, I can't promise which way things would tip. In theory, slowing the enzyme could raise side effects like nerve tingling, low blood counts, fatigue, or infection risk, while speeding it up could make the drug less effective. Given that Polivy treats a serious lymphoma, please don't add a grape supplement without first checking with your oncology team. Eating grapes as food is not a concern here.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extra
  2. Etheridge, A. S., Black, S. R., Patel, P. R., So, J., and Mathews, J. M. An in vitro evaluation of cytochrome P450 inhibition and P-glycoprotein interaction with goldenseal, Ginkgo biloba, grape seed, milk thistle, and ginseng extracts and their constitu

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

Grape Also Interacts With Other Medications

Grape has 867 moderate, 42 minor known drug interactions in our database — the Polatuzumab Vedotin-Piiq one above is one of them. If you take anything else, check it against the full list below.

Moderate 867 Minor 42 No known interaction 1,921 (incl. Polatuzumab Vedotin-Piiq)
Taking anything else?

Check Another of Your Medications Against Grape

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

From our Q&A

Questions About Grape or Polatuzumab Vedotin-Piiq

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Grape or Polatuzumab Vedotin-Piiq, 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 Polatuzumab Vedotin-Piiq

This page covers Grape only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Polatuzumab Vedotin-Piiq page lists 151 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Grapefruit (major), Siberian Cocklebur (major), St. John's Wort (major) and Wine (major).

By severity: 5 major · 117 moderate · 29 minor.

From our pharmacist’s overview on the Polatuzumab Vedotin-Piiq page

“Polivy (polatuzumab vedotin-piiq) is an IV antibody therapy for large B-cell lymphoma, and the 151 supplements and herbs on this page warrant genuine care, starting with the five rated major. Nearly every entry touches one of two pressure points.”

Reviewed by 2 · Jul 18, 2026

Open the Polatuzumab Vedotin-Piiq interaction page

One more smart check

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

We hold 8,053 real supplement products containing Grape, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Grape. Your product may carry other ingredients that interact with Polatuzumab Vedotin-Piiq too, on top of Grape — 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 Grape and Polatuzumab Vedotin-Piiq 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 Grape
Top 5%

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

29 days ago today
Medication Polatuzumab Vedotin-Piiq
Steady interest

#2,013 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 Grape

What is Grape?

Grape
  • Antioxidant support
  • Heart and circulation health
  • Vein problems (such as varicose veins)
  • Eye health
  • General anti-inflammatory support

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and blood vessel health. While the food is healthy and generally safe, the supplement evidence for treating specific conditions is mostly limited or preliminary. Talk with your pharmacist or doctor before starting a grape supplement.

Read the full Grape monograph & all interactions
Medication

About Polatuzumab vedotin-piiq Injection

What Is Polatuzumab vedotin-piiq Injection Used For?

Brand name: Polivy

  • Polatuzumab vedotin-piiq injection is used along with bendamustine (Belrapzo, Treanda) and rituximab (Rituxan) in adults to treat a certain type of non-Hodgkin's lymphoma (NHL; a type of cancer that begins in a type of white blood cells that normally fights infection) that did not improve or improved but returned after treatment with at least two other chemotherapy medications. Polatuzumab vedotin-piiq is in a class of medications called antibody-drug conjugates. It works by killing cancer cells.

See full Polatuzumab vedotin-piiq Injection drug information
Keep checking

Other Drugs & Grape

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

0Major
867Moderate
42Minor
1,920No known interaction
867 Moderate 42 Minor 1,920 No interaction
Moderate

867 interactions

Showing 60 of 867 moderate interactions — see all 867 on the Grape page.

Minor

42 interactions

No interaction 1,920 drugs checked — show the list

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

Showing the 60 most looked-up of 1,920 medications checked with no known interaction — see the full Grape list.

See the full Grape interactions page
See every supplement checked against Polatuzumab Vedotin-Piiq, 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
Grape monograph › Uses, safety, and every drug interaction in one place Polatuzumab Vedotin-Piiq supplement interactions › Every supplement checked against Polatuzumab Vedotin-Piiq, ranked by severity Polatuzumab vedotin-piiq 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 Grape and Polatuzumab Vedotin-Piiq Together: Common Questions

Can you take Grape with Polatuzumab Vedotin-Piiq?
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 Grape and Polatuzumab Vedotin-Piiq 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 Polatuzumab Vedotin-Piiq and Grape?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.