Drug & supplement interaction

Turkey Tail Mushroom + Mefenamic Acid

Mefenamic Acid brand name: Ponstel.

Minor Interaction
The bottom line Minor

Turkey Tail Mushroom has a minor interaction with Mefenamic Acid. Theoretically, the polysaccharide peptide (PSP) component of turkey tail mushroom might inhibit CYP2C9.

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

Turkey Tail Mushroom and Mefenamic Acid

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

Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Why this applies to Mefenamic Acid

Mefenamic Acid falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Turkey Tail Mushroom interacts with.

Theoretically, the polysaccharide peptide (PSP) component of turkey tail mushroom might inhibit CYP2C9.
Laboratory research suggests that the PSP component of turkey tail mushroom dose-dependently inhibits CYP2C9. Theoretically, taking PSP with drugs metabolized by CYP2C9 might increase drug levels and the risk of adverse effects. However, this has not been reported in humans.
Severity Minor 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 for these two together. Your body relies on a liver enzyme called CYP2C9 to break down mefenamic acid (Ponstel). In a lab setting, the PSP compound found in turkey tail seemed to slow that enzyme down. If that happened in a real person, the drug could clear a little slower and build up, which in theory might nudge up the usual NSAID side effects like stomach upset, heartburn, or irritation of the stomach lining.

That said, I want to keep this in perspative. This is only test-tube research, and nothing like it has actually been reported in people taking both. The interaction is rated minor. Still, since everyone's situation differs, it's worth a quick chat with your pharmacist or doctor before pairing them, especially if you take mefenamic acid regularly.

References
  1. Yeung JH and Or PM. Polysaccharide peptides from Coriolus versicolor competitively inhibit tolbutamide 4-hydroxylation in specific human CYP2C9 isoform and pooled human liver microsomes. Phytomedicine 2011;18(13):1170-5. 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

Turkey Tail Mushroom Also Interacts With Other Medications

Turkey Tail Mushroom has 88 moderate, 98 minor known drug interactions in our database — the Mefenamic Acid one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Turkey Tail Mushroom

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

Everything else you take

See Every Supplement That Interacts With Mefenamic Acid

This page covers Turkey Tail Mushroom only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Mefenamic Acid page lists 118 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Siberian Cocklebur (major) and Wine (major).

By severity: 5 major · 86 moderate · 27 minor.

From our pharmacist’s overview on the Mefenamic Acid page

“Mefenamic acid (Ponstel), an NSAID mostly used for menstrual cramps and short-term pain, has a supplement list that earns genuine caution, and the five major-rated entries are where to start. Beer and wine are two of them, because alcohol plus any NSAID raises the risk of stomach and intestinal bleeding.”

Reviewed by 2 · Jul 18, 2026

Open the Mefenamic Acid interaction page

How much people look this up

Where Turkey Tail Mushroom and Mefenamic Acid 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 Turkey Tail Mushroom
Top half

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

29 days ago today
Medication Mefenamic Acid
Top half

#1,349 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 Turkey Tail Mushroom

What is Turkey Tail Mushroom?

Turkey Tail Mushroom
  • Immune support
  • Used alongside cancer care
  • Gut and digestive health
  • General wellness and energy
  • Antioxidant support

Turkey tail is a woodland mushroom rich in polysaccharides like beta-glucans, and it is mainly used to support the immune system. Some of its purified extracts (PSK and PSP) have been studied as add-on treatments alongside conventional cancer therapy in Asia, but evidence for everyday supplement use is limited. It is generally well tolerated, but talk to your pharmacist or doctor before using it, especially if you have a health condition or take other medicines.

Read the full Turkey Tail Mushroom monograph & all interactions
Medication

About Mefenamic Acid

What Is Mefenamic Acid Used For?

Brand name: Ponstel

Mefenamic acid capsules are approved to manage mild to moderate pain in adults and adolescents 14 years of age and older, but only for short-term use — no longer than 7 days.

They are also approved to treat primary dysmenorrhea (painful menstrual periods), started at the onset of bleeding and associated symptoms.

See full Mefenamic Acid drug information
Keep checking

Other Drugs & Turkey Tail Mushroom

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

0Major
88Moderate
98Minor
2,643No known interaction
Moderate

88 interactions

Showing 60 of 88 moderate interactions — see all 88 on the Turkey Tail Mushroom page.

Minor

98 interactions

Showing 60 of 98 minor interactions — see all 98 on the Turkey Tail Mushroom page.

No interaction 2,643 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Turkey Tail Mushroom and Mefenamic Acid Together: Common Questions

Can you take Turkey Tail Mushroom with Mefenamic Acid?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Turkey Tail Mushroom and Mefenamic Acid interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

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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.