Drug & supplement interaction

Wasabi + Phenytoin

Phenytoin brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Wasabi and Phenytoin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Wasabi and Phenytoin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Phenytoin and Wasabi in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Wasabi safety at a glance

Wasabi overall Use caution Generally safe as a food, but supplement-strength doses are not well studied in people.
Pregnancy Use caution Food amounts are likely fine, but avoid concentrated supplements due to a lack of safety data.
Breastfeeding Use caution Food amounts are likely fine, but supplement doses have not been studied, so caution is best.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Phenytoin and Wasabi? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Phenytoin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Phenytoin is filed under 14 classifications — including cytochrome p450 2c8 (cyp2c8) substrates, cytochrome p450 2c9 (cyp2c9) inducers, anticonvulsants. Wasabi has documented interactions with 1 drug class — the most serious being anticoagulant/antiplatelet drugs (moderate) — and none of Phenytoin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Wasabi Does Interact With Other Medications

Wasabi has 122 moderate known drug interactions in our database — Phenytoin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 122 No known interaction 2,708 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against Wasabi

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

What to actually watch for

What Wasabi Itself Has Been Linked To

This is not an interaction — nothing below involves Phenytoin. It is the side-effect record for Wasabi on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Wasabi, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on Additional detail

    “A small clinical study in adults taking oral wasabi extract 1000 mg once daily for 4 weeks has found 2 cases of proteinuria.”

    Wasabi · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    1 source cited
    1. 112846. Nakajima R, Kanou M, Tokushima M, Iwama Y, Yamana K. Oral administration of 6-methylsulfinylhexyl isothiocyanate extracted from wasabi is safe and improves the fatigue and sleep of healthy volunteers. Biopsychosoc Med 2023;17(1):30. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Wasabi — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Phenytoin’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Phenytoin column appears here.

From our Q&A

Questions About Wasabi or Phenytoin

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

This page covers Wasabi only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenytoin page lists 224 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), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 9 major · 187 moderate · 28 minor.

From our pharmacist’s overview on the Phenytoin page

“Phenytoin (Dilantin) is a seizure medicine with a narrow therapeutic index, meaning small changes in its blood level can bring seizures back or tip over into toxicity, so I treat its supplement list with real seriousness. The biggest group, 78 ingredients, piles on sedation, and alcohol, kava, and GHB all rate major for exactly that re…”

Reviewed by 2 · Jul 18, 2026

Open the Phenytoin interaction page

How much people look this up

Where Wasabi and Phenytoin 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 Wasabi
Steady interest

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

29 days ago today
Medication Phenytoin
Top 25%

#557 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Wasabi reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Wasabi and Phenytoin records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Wasabi

What is Wasabi?

Wasabi
  • Flavoring for sushi and other foods
  • Antimicrobial support
  • Anti-inflammatory support
  • Antioxidant support
  • General immune support

Wasabi is best known as the pungent green condiment served with sushi, made from a Japanese plant in the cabbage family. Its natural compounds (isothiocyanates) show antimicrobial and antioxidant activity in lab studies, but there is very little human research to support taking it as a supplement. As a food it is generally safe; as a concentrated supplement, talk with your pharmacist or doctor first.

Eutrema japonicum · Brassicaceae · Rhizome (root stem), and sometimes the leaves and stalks · Fresh paste, dried powder, capsules, extracts, and as a culinary condiment

An interaction check asks whether these two react with each other — it does not ask whether Wasabi is a good idea for someone in your situation. Here is what our Wasabi record says about it on its own.

Wasabi: dosing

There is no established standard dose for wasabi as a supplement. Research has not identified a safe and effective amount for any specific health purpose.If you choose to use a wasabi product, follow the directions on the label and do not exceed the recommended amount.

From our Wasabi monograph — the full record covers uses, side effects and every documented interaction.

Read the full Wasabi monograph & all interactions
Medication

About Phenytoin

What Is Phenytoin Used For?

Brand names: Dilantin Kapseals, Dilantin, Di-Phen, Dilantin Infatabs, Phenytek, Dilantin injection

Phenytoin is used to treat and prevent seizures. The specific types covered depend on the formulation. Oral extended-release capsules (including Phenytek), chewable tablets (including Dilantin Infatabs and Phenytoin Infatabs), and oral suspension (including Dilantin-125) are used for tonic-clonic (grand mal) and psychomotor (temporal lobe) seizures; most oral forms also cover prevention and treatment of seizures occurring during or after neurosurgery. Chewable tablets and some capsule formulations also cover complex partial seizures.

Parenteral (injectable) phenytoin sodium is used for generalized tonic-clonic status epilepticus (a prolonged, life-threatening seizure emergency) and for prevention and treatment of seizures during neurosurgery. The IV form can also substitute short-term for oral phenytoin when a patient cannot take it by mouth.

Most-Reported Side Effects for Phenytoin

From FAERS, the FDA’s public side-effect reporting system (40,278 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Convulsion 3,522 reports
Seizure 3,095 reports
Toxicity to various agents 1,888 reports
Fall 1,604 reports
Dizziness 1,539 reports
See full Phenytoin drug information
Keep checking

Other Drugs & Wasabi

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

0Major
122Moderate
0Minor
2,707No known interaction
122 Moderate 2,707 No interaction
Moderate

122 interactions

Showing 60 of 122 moderate interactions — see all 122 on the Wasabi page.

No interaction 2,707 drugs checked — show the list

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

Showing the 60 most looked-up of 2,707 medications checked with no known interaction — see the full Wasabi list.

See the full Wasabi interactions page
See every supplement checked against Phenytoin, ranked by severity
Evidence & sources

Wasabi References

The 2 references that drive our Wasabi monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Morimitsu, Y., Hayashi, K., Nakagawa, Y., Fujii, H., Horio, F., Uchida, K., and Osawa, T. Antiplatelet and anticancer isothiocyanates in Japanese domestic horseradish, Wasabi. Mech Ageing Dev 2000;116(2-3):125-134. PubMed
  2. Nakajima R, Kanou M, Tokushima M, Iwama Y, Yamana K. Oral administration of 6-methylsulfinylhexyl isothiocyanate extracted from wasabi is safe and improves the fatigue and sleep of healthy volunteers. Biopsychosoc Med 2023;17(1):30. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Wasabi and Phenytoin Together: Common Questions

Is it safe to take Wasabi with Phenytoin?
We do not list a known interaction between Wasabi and Phenytoin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Wasabi and Phenytoin combination checked?
Interactions in our licensed database are recorded against drug classes. Phenytoin is filed under 14 classifications, and Wasabi has documented interactions with 1 drug class — none of Phenytoin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Wasabi interact with any other medications?
Yes. Wasabi has 122 documented drug interactions in our database — Phenytoin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Phenytoin interact with any supplements?
Yes. Phenytoin has documented interactions with 224 supplements in our database — Wasabi is not one of them. The Phenytoin interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Wasabi monograph Uses, safety profile, and every drug interaction in one place Phenytoin drug information The full plain-English guide to this medication Phenytoin supplement interactions Every supplement checked against Phenytoin, 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 References The 2 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Phenytoin and Wasabi?

Our pharmacists answer your medication & supplement questions — free.

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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.