Drug & supplement interaction

Tree Turmeric + Phenytoin

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

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

Phenytoin falls into 2 drug categories that Tree Turmeric can interact with; the most serious is rated moderate. Theoretically, use of tree turmeric along with CNS depressants might increase the risk of additive therapeutic and adverse effects.

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

Tree Turmeric and Phenytoin

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

Why Are There 2 Interactions?

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

Moderate

CNS DEPRESSANTS

1 of 2

Why this applies to Phenytoin

Phenytoin falls under CNS DEPRESSANTS — the group Tree Turmeric interacts with.

Theoretically, use of tree turmeric along with CNS depressants might increase the risk of additive therapeutic and adverse effects.
Animal research suggests that berberine, a constituent of tree turmeric, can have sedative effects.
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 simple version: tree turmeric (and its main active compound, berberine) has shown sedative effects in animal studies. Phenytoin, your seizure medicine, can already make some people feel drowsy, tired, or unsteady on their feet. Putting the two together could, in theory, stack those calming effects and leave you more sleepy or dizzy than usual.

I want to be honest about the evidence, though. This concern comes only from lab and animal research, not from solid human studies, so it's more of a theoretical caution than a proven problem. Phenytoin is also a medication where blood levels need to stay in a tight range, so any new supplement is worth a quick check. Please talk with your pharmacist or doctor before adding tree turmeric, and don't change your phenytoin on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
  2. Shanbhag, S. M., Kulkarni, H. J., and Gaitonde, B. B. Pharmacological actions of berberine on the central nervous system. Jpn.J Pharmacol 1970;20(4):482-487. PubMed
  3. Peng, W. H., Hsieh, M. T., and Wu, C. R. Effect of long-term administration of berberine on scopolamine-induced amnesia in rats. Jpn J Pharmacol 1997;74(3):261-266. DOI
  4. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

2 of 2

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

Theoretically, tree turmeric might increase the levels and clinical effects of drugs metabolized by CYP2C9.
Preliminary clinical evidence suggests that berberine, a constituent of tree turmeric, can inhibit CYP2C9.
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 thing about phenytoin: your liver clears it largely through an enzyme called CYP2C9. The berberine in tree turmeric appears to slow that enzyme down a bit. So in theory, less of your phenytoin gets broken down, and the level in your blood can creep up.

Why that matters: phenytoin is a narrow therapeutic index drug, meaning the gap between a helpful dose and a toxic one is small. Even a modest rise can bring on side effects like dizziness, unsteady walking, slurred speech, double vision, or drowsiness. To be clear, this comes from limited, lower-quality evidence, so it's a precaution, not a certainty. Please don't start or stop anything on your own. Just check with your pharmacist or doctor first, since they may want to watch your phenytoin level.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217. 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

Tree Turmeric Also Interacts With Other Medications

Tree Turmeric has 2 major, 1,157 moderate known drug interactions in our database — the Phenytoin one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 1,157 No known interaction 1,671 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against Tree Turmeric

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

From our Q&A

Questions About Tree Turmeric 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 Tree Turmeric 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 Tree Turmeric 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

One more smart check

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

We hold 51 real supplement products containing Tree Turmeric, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Tree Turmeric. Your product may carry other ingredients that interact with Phenytoin too, on top of Tree Turmeric — 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 Tree Turmeric 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 Tree Turmeric
Top half

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

29 days ago today
Medication Phenytoin
Steady interest

#1,745 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 Tree Turmeric

What is Tree Turmeric?

  • Blood sugar support
  • High cholesterol
  • Digestive complaints
  • Skin and eye conditions
  • Antimicrobial uses
  • Liver support

Tree turmeric (Berberis aristata) is a shrub used in traditional Indian (Ayurvedic) medicine, valued mainly for its berberine content. Early research suggests possible benefits for blood sugar and cholesterol, but high-quality human evidence is limited. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Tree Turmeric 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.

See full Phenytoin drug information
Keep checking

Other Drugs & Tree Turmeric

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

2Major
1,157Moderate
0Minor
1,670No known interaction
2 Major 1,157 Moderate 1,670 No interaction
Major

2 interactions

Moderate

1,157 interactions

Showing 60 of 1,157 moderate interactions — see all 1,157 on the Tree Turmeric page.

No interaction 1,670 drugs checked — show the list

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

Showing the 60 most looked-up of 1,670 medications checked with no known interaction — see the full Tree Turmeric list.

See the full Tree Turmeric interactions page
See every supplement checked against 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
Tree Turmeric monograph › Uses, safety, and every drug interaction in one place Phenytoin supplement interactions › Every supplement checked against Phenytoin, ranked by severity Phenytoin drug information › The full plain-English guide to this medication 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 Tree Turmeric and Phenytoin Together: Common Questions

Can you take Tree Turmeric with Phenytoin?
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 2 interactions listed for Tree Turmeric and Phenytoin?
Phenytoin belongs to more than one drug category, and Tree Turmeric 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 Tree Turmeric and Phenytoin 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 Phenytoin and Tree Turmeric?

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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.