Drug & supplement interaction

Green Tea + Imatinib

Imatinib brand name: Gleevec.

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

Imatinib falls into 2 drug categories that Green Tea can interact with; the most serious is rated moderate. Theoretically, green tea might reduce the levels and clinical effects of imatinib.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Green Tea and Imatinib

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Green Tea interacts with whole categories of medication. Imatinib falls into 2 of those categories, so it can interact with Green Tea in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

IMATINIB (Gleevec)

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Theoretically, green tea might reduce the levels and clinical effects of imatinib.
In animal research, a single dose of green tea extract reduces the area under the curve (AUC) of imatinib by up to approximately 64% and its main metabolite N-desmethyl imatinib by up to approximately 81%. This interaction has not been shown in humans. The mechanism of action is unclear but may involve multiple pathways.
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 gist with imatinib (Gleevec) and green tea. Imatinib is an active drug on its own, not a prodrug, so it doesn't need to be switched on by your body to work. The concern on file is that green tea might lower the amount of imatinib your body absorbs and keeps around. If imatinib levels drop, the medicine may not control your leukemia or tumor as well as it should, which matters a lot with a cancer drug.

Now, the honest part: this comes from animal and lab studies only, where big doses of green tea extract cut imatinib levels sharply. It has not been shown in people. A cup or two of regular green tea is unlikely to be a problem, but concentrated extract pills are a different question. Before adding any green tea supplement, please check with your pharmacist or oncologist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Darweesh RS, El-Elimat T, Zayed A, et al. The effect of grape seed and green tea extracts on the pharmacokinetics of imatinib and its main metabolite, N-desmethyl imatinib, in rats. BMC Pharmacol Toxicol. 2020;21(1):77. PubMed
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

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Why this applies to Imatinib

Imatinib falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Green Tea interacts with.

Green tea is unlikely to produce clinically significant changes in the levels and clinical effects of CYP3A4 substrates.
In vitro and in vivo research suggests that green tea can inhibit intestinal CYP3A and induce hepatic CYP3A4 enzymes. However, this effect is unlikely to be clinically significant, as green tea does not appear to affect CYP3A4 activity in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the simple version: your body uses an enzyme called CYP3A4 to process imatinib (Gleevec), and green tea has shown some activity on that same enzyme in lab and animal studies. In theory, green tea could nudge imatinib levels up or down a bit, which might mean either more side effects (nausea, fluid retention, muscle cramps, low blood counts) or slightly less benefit against the cancer.

The good news is that in actual human studies, green tea doesn't seem to meaningfully change how this enzyme works, so an everyday cup of tea is very unlikely to cause a problem. Concentrated green tea extract pills are a bigger unknown, and high doses can stress the liver, which matters since imatinib can too. Before adding any green tea supplement, check with your oncology pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8. PubMed
  2. 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 extrac
  3. Chow, H. H., Hakim, I. A., Vining, D. R., Crowell, J. A., Cordova, C. A., Chew, W. M., Xu, M. J., Hsu, C. H., Ranger-Moore, J., and Alberts, D. S. Effects of repeated green tea catechin administration on human cytochrome P450 activity. Cancer Epidemiol.B PubMed
  4. Engdal, S. and Nilsen, O. G. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother.Res. 2009;23(7):906-912.
  5. Schönthal AH. Adverse effects of concentrated green tea extracts. Mol Nutr Food Res. 2011 Jun;55(6):874-85. 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

Green Tea Also Interacts With Other Medications

Green Tea has 13 major, 904 moderate, 375 minor known drug interactions in our database — the Imatinib one above is among them. If you take anything else, check it against the full list below.

Major 13 Moderate 904 Minor 375 No known interaction 1,538 (incl. Imatinib)
Taking anything else?

Check Another of Your Medications Against Green Tea

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

From our Q&A

Questions About Green Tea or Imatinib

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Green Tea or Imatinib, 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 Imatinib

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Imatinib page lists 153 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 8 major · 106 moderate · 39 minor.

From our pharmacist’s overview on the Imatinib page

“Imatinib (Gleevec) treats certain leukemias and gastrointestinal tumors, and because keeping its blood level steady is what keeps the cancer controlled, this list deserves genuine attention before you add anything to it. Most of the interactions trace back to how the body clears imatinib through an enzyme called CYP3A4.”

Reviewed by 2 · Jul 18, 2026

Open the Imatinib interaction page

One more smart check

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

We hold 9,084 real supplement products containing Green Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Green Tea. Your product may carry other ingredients that interact with Imatinib too, on top of Green Tea — 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 Green Tea and Imatinib 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 Green Tea
Top 5%

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

29 days ago today
Medication Imatinib
Steady interest

#1,842 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 Green Tea

What is Green Tea?

Green Tea
  • Antioxidant support
  • Weight loss
  • Heart health
  • Mental alertness
  • Cancer risk reduction

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different story—they may help modestly with weight or heart health for some, but high doses have been linked to rare liver problems. Talk to your pharmacist or doctor before taking green tea supplements, especially if you have liver concerns or are pregnant.

Read the full Green Tea monograph & all interactions
Medication

About Imatinib

What Is Imatinib Used For?

Brand name: Gleevec

Imatinib treats a range of blood cancers and solid tumors. It is used for Philadelphia chromosome positive chronic myeloid leukemia (Ph+ CML) in adults and children — whether newly diagnosed or in more advanced phases — and for Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) in both adults and pediatric patients.

It is also used for Kit-positive gastrointestinal stromal tumors (GIST), including after surgical removal, and for several rarer conditions: myelodysplastic/myeloproliferative diseases (MDS/MPD) linked to specific gene changes, aggressive systemic mastocytosis (ASM), hypereosinophilic syndrome (HES) and/or chronic eosinophilic leukemia (CEL), and unresectable, recurrent, or metastatic dermatofibrosarcoma protuberans (DFSP).

See full Imatinib drug information
Keep checking

Other Drugs & Green Tea

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

13Major
904Moderate
375Minor
1,537No known interaction
13 Major 904 Moderate 375 Minor 1,537 No interaction
Major

13 interactions

Moderate

904 interactions

Showing 60 of 904 moderate interactions — see all 904 on the Green Tea page.

Minor

375 interactions

Showing 60 of 375 minor interactions — see all 375 on the Green Tea page.

No interaction 1,537 drugs checked — show the list

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

Showing the 60 most looked-up of 1,537 medications checked with no known interaction — see the full Green Tea list.

See the full Green Tea interactions page
See every supplement checked against Imatinib, 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
Green Tea monograph › Uses, safety, and every drug interaction in one place Imatinib supplement interactions › Every supplement checked against Imatinib, ranked by severity Imatinib 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 Green Tea and Imatinib Together: Common Questions

Can you take Green Tea with Imatinib?
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.
Why are there 2 interactions listed for Green Tea and Imatinib?
Imatinib belongs to more than one drug category, and Green Tea interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Green Tea and Imatinib 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 Imatinib and Green Tea?

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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.