Drug & supplement interaction

Peppermint + Voriconazole

Voriconazole brand name: Vfend.

Moderate Interaction
The bottom line Moderate

Voriconazole falls into 3 drug categories that Peppermint can interact with; the most serious is rated moderate. Theoretically, peppermint might increase the levels of CYP2C19 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Peppermint and Voriconazole

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Peppermint interacts with whole categories of medication. Voriconazole falls into 3 of those categories, so it can interact with Peppermint in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

1 of 3

Why this applies to Voriconazole

Voriconazole falls under CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES — the group Peppermint interacts with.

Theoretically, peppermint might increase the levels of CYP2C19 substrates.
In vitro research shows that peppermint oil inhibits CYP2C19. 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 gist: your body relies partly on a liver enzyme called CYP2C19 to break down voriconazole. Lab studies suggest peppermint oil can slow that same enzyme down. If that happened in real life, voriconazole could clear more slowly and build up a bit, which might mean stronger effects and more side effects like vision changes, nausea, headache, or liver irritation.

The good news is this is still theoretical. It has only been seen in test-tube research, not in actual patients, so the real risk is likely small. An occasional cup of peppermint tea is very unlikely to matter; concentrated peppermint oil capsules are the bigger question. Since voriconazole is a serious antifungal with tricky blood levels, just give your pharmacist or doctor a heads-up before using peppermint regularly.

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
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

2 of 3

Voriconazole also falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES.

Theoretically, peppermint might increase the levels of CYP2C9 substrates.
In vitro research shows that peppermint oil inhibits CYP2C9. 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 gist for voriconazole (Vfend): your body partly clears it using a liver enzyme called CYP2C9. In lab dish studies, peppermint oil appears to slow that same enzyme down. If that happened in people, voriconazole could clear more slowly and build up a bit in your system, which might mean stronger effects and a higher chance of side effects like visual changes, nausea, headache, or liver-related issues.

But I want to be honest about the strength of this: it's only seen in test-tube and animal work, and it has never actually been reported in real patients. Everyday culinary peppermint (like tea or a mint) is very unlikely to matter. Concentrated peppermint oil capsules are more of a question mark, so just run it by your pharmacist or doctor first.

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
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Voriconazole also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Theoretically, peppermint might increase the levels of CYP3A4 substrates.
Clinical research in healthy volunteers shows that a single dose of peppermint oil 600 mg inhibits CYP3A4 enzymes and increases the AUC of felodipine, a CYP3A4 substrate. However, in vitro research suggests that peppermint oil only inhibits CYP3A4 at very high concentrations.
Severity Moderate Likelihood Possible Evidence B

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 voriconazole (Vfend). Your body partly clears this antifungal using a liver enzyme called CYP3A4. Concentrated peppermint oil can mildly slow that same enzyme, at least in lab and small studies. In theory, that could let voriconazole build up a bit, which might mean more of its known side effects, things like visual disturbances (blurry vision or seeing brighter light), nausea, headache, or liver irritation.

Honestly though, this is a theoretical and weak concern. A peppermint tea or a mint candy almost certainly won't matter. Regular enteric-coated peppermint oil capsules for IBS are where I'd pause. Since voriconazole already needs careful dosing, just run it by your pharmacist or doctor before adding peppermint supplements.

References
  1. Dresser GK, Wacher V, Wong S, et al. Evaluation of peppermint oil and ascorbyl palmitate as inhibitors of cytochrome P4503A4 activity in vitro and in vivo. Clin Pharmacol Ther 2002;72:247-55. PubMed
  2. 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

Peppermint Also Interacts With Other Medications

Peppermint has 730 moderate, 65 minor known drug interactions in our database — the Voriconazole one above is among them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against Peppermint

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

Everything else you take

See Every Supplement That Interacts With Voriconazole

This page covers Peppermint only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Voriconazole page lists 205 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 6 major · 159 moderate · 40 minor.

From our pharmacist’s overview on the Voriconazole page

“Voriconazole (Vfend) is a heavy-hitter antifungal, usually prescribed for dangerous infections like invasive aspergillosis, and its list of 205 interacting supplements includes six rated major, enough that anyone on this drug should read those entries before touching a supplement bottle. Most interactions run through the liver enzymes…”

Reviewed by 2 · Jul 18, 2026

Open the Voriconazole interaction page

One more smart check

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

We hold 1,980 real supplement products containing Peppermint, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Peppermint. Your product may carry other ingredients that interact with Voriconazole too, on top of Peppermint — 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 Peppermint and Voriconazole 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 Peppermint
Top 10%

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

29 days ago today
Medication Voriconazole
Steady interest

#1,576 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 Peppermint

What is Peppermint?

Peppermint
  • Irritable bowel syndrome (IBS)
  • Indigestion and gas
  • Nausea
  • Tension headache (topical oil)
  • Colds and congestion
  • Freshening breath

Peppermint is a popular herb with the best evidence supporting enteric-coated peppermint oil for easing IBS symptoms. It is generally well tolerated for most adults, but it can cause heartburn and is not recommended in concentrated oil form for infants and young children. Check with your pharmacist or doctor before using it regularly, especially during pregnancy or breastfeeding.

Read the full Peppermint monograph & all interactions
Medication

About Voriconazole

What Is Voriconazole Used For?

Brand name: Vfend

Voriconazole treats several serious fungal infections. Across all available forms — tablets, oral suspension, and intravenous (IV) injection — it is used for invasive aspergillosis (a dangerous mold infection), candidemia (Candida fungus in the bloodstream) in patients who are not neutropenic (not severely low on white blood cells), other deep-tissue Candida infections, and serious infections caused by Scedosporium apiospermum or Fusarium species in patients who cannot tolerate or have not responded to other antifungal treatments.

Esophageal candidiasis (a Candida infection of the esophagus, the swallowing tube) is also an approved use for most formulations. Note on the oral tablet form (generic voriconazole tablets): that specific tablet formulation is approved for patients aged 12 to 14 years weighing at least 50 kg, and all patients 15 years and older — not for younger or smaller children. The oral suspension and the IV injection are approved for patients 2 years and older for most of these conditions.

See full Voriconazole drug information
Keep checking

Other Drugs & Peppermint

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

0Major
730Moderate
65Minor
2,034No known interaction
Moderate

730 interactions

Showing 60 of 730 moderate interactions — see all 730 on the Peppermint page.

Minor

65 interactions

Showing 60 of 65 minor interactions — see all 65 on the Peppermint page.

No interaction 2,034 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 Peppermint and Voriconazole Together: Common Questions

Can you take Peppermint with Voriconazole?
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 3 interactions listed for Peppermint and Voriconazole?
Voriconazole belongs to more than one drug category, and Peppermint 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 Peppermint and Voriconazole 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

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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.