Drug & supplement interaction

Peppermint + Proguanil

Proguanil brand name: Paludrine.

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

Peppermint has a moderate interaction with Proguanil. Theoretically, peppermint might increase the levels of CYP2C19 substrates.

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

Peppermint and Proguanil

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

Moderate

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES

Why this applies to Proguanil

Proguanil 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 a twist worth knowing about proguanil. It's actually a prodrug, meaning your body has to convert it into its active form called cycloguanil, and the enzyme CYP2C19 does most of that work. Peppermint oil, in lab studies, appears to slow that same enzyme down. So in theory, peppermint could leave you with less of the active antimalarial and a bit weaker protection.

Now, the honest part: this has only been seen in test-tube research, never in real people, so I wouldn't lose sleep over it. A little peppermint tea or a mint candy almost certainly won't matter. If you're taking concentrated peppermint oil capsules regularly while relying on proguanil to prevent malaria, 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

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 Proguanil one above is one of them. If you take anything else, check it against the full list below.

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

This page covers Peppermint only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Proguanil page lists 54 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Adrafinil (moderate), Artichoke (moderate), Bacopa (moderate) and Baikal Skullcap (moderate).

By severity: 1 major · 40 moderate · 13 minor.

From our pharmacist’s overview on the Proguanil page

“Malaria prophylaxis leaves little margin for error, so the 54 supplements and herbs on file against proguanil (Paludrine) deserve a careful read rather than a shrug. The single major-rated entry is activated charcoal, which binds medicines in the gut and can cut proguanil exposure enough to undermine your protection.”

Reviewed by 2 · Jul 18, 2026

Open the Proguanil 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 Proguanil 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 Proguanil 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 Proguanil
Steady interest

#2,695 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 Proguanil, 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 Proguanil supplement interactions › Every supplement checked against Proguanil, 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 Proguanil Together: Common Questions

Can you take Peppermint with Proguanil?
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 Peppermint and Proguanil 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 Proguanil and Peppermint?

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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.