Drug & supplement interaction

Maitake Mushroom + Warfarin

Warfarin brand name: Warfarin.

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

Maitake Mushroom has a moderate interaction with Warfarin. There is limited evidence that maitake mushroom may increase the anticoagulant effects of warfarin.

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

Maitake Mushroom and Warfarin

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

Moderate

WARFARIN (Coumadin)

There is limited evidence that maitake mushroom may increase the anticoagulant effects of warfarin.
In a case report, a patient previously stabilized on warfarin developed an elevated international normalized ratio (INR) of 5.1 after taking maitake mushroom (Grifron-Pro Maitake D-Fraction) 1 drop/kg daily in three divided doses for one week. The elevated INR resolved after holding warfarin for two days, then reducing the dose by 11%. It is thought that the beta-glucan constituent of maitake mushroom might cause warfarin dissociation from proteins, resulting in increased free warfarin levels and increased warfarin effects.
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: warfarin is a finely tuned blood thinner, and we use a blood test called the INR to make sure it's keeping you in just the right range. There's a single case report where someone stable on warfarin added a concentrated maitake mushroom product (the D-fraction drops) and their INR jumped to 5.1, which is higher than we want and raises the risk of bruising and bleeding. The thinking is that maitake may bump warfarin off the proteins it normally rides on, leaving more active drug floating free.

Now, this is anecdotal evidence from one person, so it's far from proven, and eating maitake as a food is much less concerning than taking concentrated capsules or drops. Still, because warfarin leaves so little room for error, please loop in your pharmacist or doctor before starting or stopping any maitake supplement so they can keep an eye on your INR.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hanselin MR, Vande Griend JP, Linnebur SA. INR elevation with maitake extract in combination with warfarin. Ann Pharmacother 2010;44:223-4. 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

Maitake Mushroom Also Interacts With Other Medications

Maitake Mushroom has 259 moderate known drug interactions in our database — the Warfarin one above is one of them. If you take anything else, check it against the full list below.

Moderate 259 No known interaction 2,571 (incl. Warfarin)
Taking anything else?

Check Another of Your Medications Against Maitake Mushroom

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

From our Q&A

Questions About Maitake Mushroom or Warfarin

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

This page covers Maitake Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Warfarin page lists 361 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Alfalfa (major), American Ginseng (major), Beer (major) and Cannabis (major).

By severity: 16 major · 301 moderate · 44 minor.

From our pharmacist’s overview on the Warfarin page

“People take warfarin to prevent dangerous clots, and many are the same people reaching for glucosamine for sore joints or a multivitamin containing vitamin K, which makes this a list that deserves genuine respect. Of the 361 supplements on file for warfarin, 16 carry a major rating, and the danger runs in both directions: some add to w…”

Reviewed by 2 · Jul 18, 2026

Open the Warfarin interaction page

One more smart check

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

We hold 1,788 real supplement products containing Maitake Mushroom, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Maitake Mushroom. Your product may carry other ingredients that interact with Warfarin too, on top of Maitake Mushroom — 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 Maitake Mushroom and Warfarin 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 Maitake Mushroom
Top 25%

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

29 days ago today
Medication Warfarin
Top 10

#4 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 Maitake Mushroom

What is Maitake Mushroom?

Maitake Mushroom
  • Immune support
  • Blood sugar support in diabetes
  • High blood pressure
  • High cholesterol
  • General wellness and antioxidant support

Maitake is an edible mushroom long used as food and in traditional Japanese medicine, and it is being studied for possible immune, blood sugar, and blood pressure effects. The human evidence is still limited and not strong enough to recommend it as a treatment. It is generally well tolerated as food, but talk to your pharmacist or doctor before using concentrated supplements.

Read the full Maitake Mushroom monograph & all interactions
Medication

About Warfarin

What Is Warfarin Used For?

Brand name: Warfarin

Warfarin sodium tablets and Jantoven tablets are both used to prevent and treat venous thrombosis (blood clots in the veins) and pulmonary embolism (a clot in the lungs). They are also used to prevent clot-related complications in people with atrial fibrillation (an irregular heart rhythm) or who have had a heart valve replaced.

In people who have had a heart attack, warfarin is used to reduce the risk of death, another heart attack, stroke, or other clotting events. It does not dissolve an existing clot, but it helps prevent the clot from growing and stops new dangerous clots from forming.

See full Warfarin drug information
Keep checking

Other Drugs & Maitake Mushroom

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

0Major
259Moderate
0Minor
2,570No known interaction
259 Moderate 2,570 No interaction
Moderate

259 interactions

Showing 60 of 259 moderate interactions — see all 259 on the Maitake Mushroom page.

No interaction 2,570 drugs checked — show the list

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

Showing the 60 most looked-up of 2,570 medications checked with no known interaction — see the full Maitake Mushroom list.

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

Can you take Maitake Mushroom with Warfarin?
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 Maitake Mushroom and Warfarin 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 Warfarin and Maitake Mushroom?

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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.