Drug & supplement interaction

Peppermint + Amitriptyline, Perphenazine

Amitriptyline, Perphenazine brand names: Triavil, Etrafon, Etrafon-A, Etrafon-Forte.

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

Amitriptyline, Perphenazine falls into 4 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
Interactions4
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Peppermint and Amitriptyline, Perphenazine

These two interact in 4 distinct ways. Each one is explained separately below.

Why Are There 4 Interactions?

Peppermint interacts with whole categories of medication. Amitriptyline, Perphenazine falls into 4 of those categories, so it can interact with Peppermint in 4 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 4

Why this applies to Amitriptyline, Perphenazine

Amitriptyline, Perphenazine 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

This combination pill pairs amitriptyline (an older antidepressant) with perphenazine (an antipsychotic). Both are active drugs, not prodrugs, and your liver helps clear them using several enzymes, including CYP2C19. In the lab, peppermint oil has been shown to slow down that enzyme. In theory, that could let these medicines build up a little higher in your body, which might mean more of their usual side effects like drowsiness, dry mouth, constipation, dizziness on standing, or a faster heartbeat.

The important thing to know is that this is only seen in test-tube studies and has never been reported in real people. Everyday culinary peppermint (tea or candy) is very unlikely to matter. If you regularly use concentrated peppermint oil capsules, just mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
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 4

Amitriptyline, Perphenazine 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 your Triavil (amitriptyline plus perphenazine): in lab dishes, peppermint oil appears to slow down a liver enzyme called CYP2C9, which helps clear certain medicines. If that happened in your body, levels of these drugs could creep up a little. Since neither one is a prodrug, more in your system would mean stronger effects, things like extra drowsiness, dry mouth, constipation, blurry vision, dizziness on standing, or a faster heartbeat.

That said, this is only a theoretical concern from test-tube work, and it has never actually been reported in people. Occasional culinary peppermint or a cup of tea is very unlikely to matter. If you take concentrated peppermint oil capsules regularly, just mention it to your pharmacist or doctor so they can keep an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
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 4

Amitriptyline, Perphenazine 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

This combination pill pairs amitriptyline (an older antidepressant) with perphenazine (an antipsychotic), and your liver uses an enzyme called CYP3A4 to help clear them. Concentrated peppermint oil, like the kind in IBS capsules, can mildly slow that enzyme down. In theory, that could let a little more of these medicines build up, which might mean stronger side effects such as drowsiness, dry mouth, constipation, blurred vision, dizziness on standing, or a faster heartbeat.

That said, the evidence here is thin and mostly theoretical. A whiff of peppermint tea or a mint candy is very unlikely to matter. If you take peppermint oil capsules regularly, just give your pharmacist or doctor a heads-up so they can keep an eye on how you feel.

Contact Dr. Brian directly if you have additional questions on this interaction
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
Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

4 of 4

Amitriptyline, Perphenazine also falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES.

Theoretically, peppermint might increase the levels of CYP1A2 substrates.
In vitro and animal research shows that peppermint oil and peppermint leaf inhibit CYP1A2. However, in clinical research, peppermint tea did not significantly affect the metabolism of caffeine, a CYP1A2 substrate. It is possible that the 6-day duration of treatment may have been too short to identify a difference.
Severity Minor 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

This combination pill pairs amitriptyline (a tricyclic antidepressant) with perphenazine (an antipsychotic). Lab and animal studies suggest peppermint oil can mildly block CYP1A2, one of the enzymes your liver uses to help clear amitriptyline. In theory, slowing that breakdown could let drug levels drift up a bit, which might add to the usual side effects like drowsiness, dry mouth, constipation, blurry vision, or feeling lightheaded when you stand.

Here's the reassuring part: in actual human research, peppermint tea didn't meaningfully change how the body processed a similar CYP1A2 drug. So this is mostly theoretical and rated minor. Food and tea amounts are very unlikely to matter. If you use concentrated peppermint oil capsules regularly, just give your pharmacist a quick heads-up.

Contact Dr. Brian directly if you have additional questions on this interaction
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
  2. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9. PubMed
  3. Begas E, Tsioutsiouliti A, Kouvaras E, et al. Effects of peppermint tea consumption on the activities of CYP1A2, CYP2A6, Xanthine Oxidase, N-acetyltranferase-2 and UDP-glucuronosyltransferases-1A1/1A6 in healthy volunteers. Food Chem Toxicol 2017;100:80-9 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 Amitriptyline, Perphenazine one above is among them. If you take anything else, check it against the full list below.

Moderate 730 Minor 65 No known interaction 2,035 (incl. Amitriptyline, Perphenazine)
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 Amitriptyline, Perphenazine

This page covers Peppermint only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Amitriptyline, Perphenazine page lists 311 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), American Hellebore (major), Arsenic (major) and Beer (major).

By severity: 19 major · 235 moderate · 57 minor.

From our pharmacist’s overview on the Amitriptyline, Perphenazine page

“Alcohol is the risk I'd flag first for anyone taking amitriptyline with perphenazine (Triavil, Etrafon). Beer and wine both carry major ratings here, and 78 of the 311 ingredients on file deepen the drowsiness this antidepressant and antipsychotic combination already causes, sometimes to the point of slowed breathing.”

Reviewed by 2 · Jul 18, 2026

Open the Amitriptyline, Perphenazine 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 Amitriptyline, Perphenazine 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 Amitriptyline, Perphenazine 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 Amitriptyline, Perphenazine
Top half

#1,336 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
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
730 Moderate 65 Minor 2,034 No 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

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

Showing the 60 most looked-up of 2,034 medications checked with no known interaction — see the full Peppermint list.

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

Can you take Peppermint with Amitriptyline, Perphenazine?
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 4 interactions listed for Peppermint and Amitriptyline, Perphenazine?
Amitriptyline, Perphenazine 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 Amitriptyline, Perphenazine 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.