Drug & supplement interaction

Ginger + Phenobarbital, Phenytoin

Phenobarbital, Phenytoin brand name: Dilantin with PB.

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

Phenobarbital, Phenytoin falls into 2 drug categories that Ginger can interact with; the most serious is rated minor. Theoretically, ginger might increase the levels of CYP2C9 substrates.

Read the full interaction report
SeverityMinor
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Ginger and Phenobarbital, Phenytoin

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Ginger interacts with whole categories of medication. Phenobarbital, Phenytoin falls into 2 of those categories, so it can interact with Ginger in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Minor).

Minor

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

1 of 2

Why this applies to Phenobarbital, Phenytoin

Phenobarbital, Phenytoin falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Ginger interacts with.

Theoretically, ginger might increase the levels of CYP2C9 substrates.
In vitro research shows that ginger inhibits CYP2C9 activity. However, this interaction 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 short version: this combination is mostly a theoretical concern. Phenytoin is partly cleared by a liver enzyme called CYP2C9. In a lab dish, ginger seemed to slow that enzyme down, which could let phenytoin build up a little. But this has never actually been reported in real people, so the worry is on paper, not in practice.

Phenytoin matters here because it has a narrow safety window, meaning small changes in its level can tip you from helpful into too much. If levels crept up, you might notice signs like dizziness, unsteady walking, slurred speech, double vision, or unusual drowsiness. Normal cooking amounts of ginger are very unlikely to cause trouble. If you want to take regular ginger supplements, just check with your pharmacist or doctor first so they can keep an eye on things.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Husain I, Dale OR, Idrisi M, et al. Evaluation of the Herb-Drug Interaction (HDI) Potential of Zingiber officinale and Its Major Phytoconstituents. J Agric Food Chem. 2023;71(19):7521-7534.
Minor

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES

2 of 2

Phenobarbital, Phenytoin also falls under CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES.

Theoretically, ginger might increase the levels of CYP2B6 substrates.
In vitro research shows that ginger inhibits CYP2B6 activity. However, this interaction 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 honest version: this is a very early, lab-only finding. In test-tube studies, ginger appears to slow down an enzyme called CYP2B6, which helps your body process certain drugs, including phenobarbital. In theory, if that enzyme is blocked, more phenobarbital could hang around in your system. With a build-up you might notice extra drowsiness, dizziness, grogginess, or feeling unsteady.

But here's the key point: this has never actually been seen in real people, only in a dish in a lab. Food-amounts of ginger are very unlikely to matter. Concentrated ginger supplements are a bit more of a question mark. Since phenobarbital and phenytoin are sensitive medicines where levels count, just give your pharmacist or doctor a heads-up before starting ginger pills.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Husain I, Dale OR, Idrisi M, et al. Evaluation of the Herb-Drug Interaction (HDI) Potential of Zingiber officinale and Its Major Phytoconstituents. J Agric Food Chem. 2023;71(19):7521-7534.

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

Ginger Also Interacts With Other Medications

Ginger has 874 moderate, 132 minor known drug interactions in our database — the Phenobarbital, Phenytoin one above is among them. If you take anything else, check it against the full list below.

Moderate 874 Minor 132 No known interaction 1,824 (incl. Phenobarbital, Phenytoin)
Taking anything else?

Check Another of Your Medications Against Ginger

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

From our Q&A

Questions About Ginger or Phenobarbital, 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 Ginger or Phenobarbital, 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 Phenobarbital, Phenytoin

This page covers Ginger only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenobarbital, Phenytoin page lists 229 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 · 192 moderate · 28 minor.

From our pharmacist’s overview on the Phenobarbital, Phenytoin page

“If your seizure medicine is the phenobarbital and phenytoin combination (Dilantin with PB), read this list carefully before you add any supplement. Nine of the 229 entries rate major, and most of the risk runs through two channels.”

Reviewed by 2 · Jul 18, 2026

Open the Phenobarbital, Phenytoin interaction page

One more smart check

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

We hold 9,640 real supplement products containing Ginger, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Ginger. Your product may carry other ingredients that interact with Phenobarbital, Phenytoin too, on top of Ginger — 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 Ginger and Phenobarbital, 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 Ginger
Top 5%

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

29 days ago today
Medication Phenobarbital, Phenytoin
Steady interest

#2,191 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 Ginger

What is Ginger?

Ginger
  • Nausea and vomiting
  • Motion sickness
  • Morning sickness in pregnancy
  • Digestive upset
  • Menstrual cramps
  • Joint pain and inflammation

Ginger is a widely used culinary spice with a long history in traditional medicine, and it has the strongest evidence for helping with nausea and vomiting, including from motion sickness, pregnancy, and chemotherapy. It is generally safe in food and supplement amounts for most people, though it may cause mild stomach upset. Talk with your pharmacist or doctor before using ginger supplements, especially if you are pregnant, have a bleeding disorder, or take other medicines.

Read the full Ginger monograph & all interactions
Keep checking

Other Drugs & Ginger

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

0Major
874Moderate
132Minor
1,823No known interaction
874 Moderate 132 Minor 1,823 No interaction
Moderate

874 interactions

Showing 60 of 874 moderate interactions — see all 874 on the Ginger page.

Minor

132 interactions

Showing 60 of 132 minor interactions — see all 132 on the Ginger page.

No interaction 1,823 drugs checked — show the list

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

Showing the 60 most looked-up of 1,823 medications checked with no known interaction — see the full Ginger list.

See the full Ginger interactions page
See every supplement checked against Phenobarbital, Phenytoin, 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
Ginger monograph › Uses, safety, and every drug interaction in one place Phenobarbital, Phenytoin supplement interactions › Every supplement checked against Phenobarbital, 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 Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Ginger and Phenobarbital, Phenytoin Together: Common Questions

Can you take Ginger with Phenobarbital, Phenytoin?
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.
Why are there 2 interactions listed for Ginger and Phenobarbital, Phenytoin?
Phenobarbital, Phenytoin belongs to more than one drug category, and Ginger 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 Ginger and Phenobarbital, Phenytoin 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

Still Have a Question About Phenobarbital, Phenytoin and Ginger?

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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.