Medication interaction hub

What Supplements Interact with Phenobarbital, Phenytoin?

Phenobarbital, Phenytoin brand name: Dilantin with PB. Every interaction below applies to the brands too.

229 Interactions 9 Major 192 Moderate 28 Minor
Curated & coded by · Clinical Pharmacist · Updated October 1, 2026

Drug–supplement interaction data sourced from Natural Medicines Pro, the licensed clinical database from TRC Healthcare / Therapeutic Research, with additional analysis by the HelloPharmacist Pharmacist Team. Our sources · Editorial policy

What is this page for?

One answer, for one medication: what supplements and herbal products interact with Phenobarbital, Phenytoin? Every vitamin, herb, and supplement ingredient we’ve checked against it is on this page, ranked by severity, each linking to the full report for that exact pair.

This page covers supplement interactions only — to check Phenobarbital, Phenytoin against your other medications, use the drug–drug interaction checker. Educational information from our licensed clinical databases, not medical advice. Our editorial policy

HelloPharmacist Bottom Line
Our Pharmacist Explains
What is this? The interaction data in the HelloPharmacist supplement database is licensed from Natural Medicines Pro by TRC Healthcare (Therapeutic Research). HelloPharmacist pharmacists often add our own analysis and context on top of that licensed data — such as this Bottom Line summary and the notes on individual interaction pages — and any such commentary is noted as ours.

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. Seventy-eight ingredients pile extra sedation onto drugs that already slow you down, with alcohol in any form the clearest example, and 38 can stress a liver that these medicines already work hard. St. John's wort stands out for a different reason, since it can drop phenobarbital levels enough to threaten seizure control.

The remaining entries, 192 moderate and 28 minor, mostly shift how your body processes these drugs or block their absorption in the gut. Even folic acid can work against phenobarbital in some people. Start with the nine major entries, then check anything you already take against the rest of the page.

— , Clinical Pharmacist · July 18, 2026

Major 9 Moderate 192 Minor 28 No known interaction 1,223

This box checks one ingredient at a time (like turmeric or magnesium). Taking a supplement product with a whole label of ingredients? Search the product instead — we check every ingredient on it ↓

Top Ingredient Interactions

Phenobarbital, Phenytoin: Top Interactions at a Glance

The most significant Phenobarbital, Phenytoin supplement & herbal interactions, colored by severity. Tap any ingredient to open the full report for that pair.

Showing the 12 highest-ranked of 229 interacting ingredients — plus 1,223 more checked with no known interaction. See the complete ranked list.

Start here

The Major Interactions to Know About

The most clinically significant Phenobarbital, Phenytoin + supplement combinations in our database, best-documented first. Open any card for the full report.

Major Likelihood Likely Beer + Phenobarbital, Phenytoini

Concomitant use may increase sedative and other adverse effects.

Read the full interaction Major Likelihood Likely Siberian Cocklebur + Phenobarbital, Phenytoini

Siberian cocklebur can adversely affect the liver.

Read the full interaction Major Likelihood Likely St. John's Wort + Phenobarbital, Phenytoini

St.

Read the full interaction Major Likelihood Likely Wine + Phenobarbital, Phenytoini

Concomitant use may increase sedative and other adverse effects.

Read the full interaction Major Likelihood Probable 1,4-butanediol + Phenobarbital, Phenytoini

Theoretically, concomitant use of 1,4-butanediol with CNS depressants may potentiate respiratory and CNS depression.

Read the full interaction Major Likelihood Probable Activated Charcoal + Phenobarbital, Phenytoini

Activated charcoal reduces systemic exposure to many drugs, including those that undergo enterohepatic recirculation, regardless of the route of administration.

Read the full interaction
The complete list

Every Supplement Checked Against Phenobarbital, Phenytoin

All 1,452 ingredients in our database, ranked by severity — 229 with a Phenobarbital, Phenytoin interaction on file and 1,223 with none found. Filter by severity or search any ingredient; hover the for what each ingredient is.

Looking for an interaction with a specific supplement product? Search products instead ↓

Straight answers

Can You Take It With Phenobarbital, Phenytoin?

One-line answers, one card per combination — scroll through today’s 20 and tap any card for the full report. A different set rotates in daily until every combination has had its turn.

Can you take Caffeine with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, caffeine might reduce the effects of phenobarbital and increase the risk for convulsions.

Full Caffeine + Phenobarbital, Phenytoin answer

Can you take Rhodiola with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, rhodiola might increase levels of drugs metabolized by CYP2C9.

Full Rhodiola + Phenobarbital, Phenytoin answer

Can you take Peppermint with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, peppermint might increase the levels of CYP2C19 substrates.

Full Peppermint + Phenobarbital, Phenytoin answer

Can you take Phellodendron with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, phellodendron might increase the sedative effects of CNS depressants.

Full Phellodendron + Phenobarbital, Phenytoin answer

Can you take Phenibut with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, phenibut might increase the risk of sedation and respiratory depression when taken with CNS depressants.

Full Phenibut + Phenobarbital, Phenytoin answer

Can you take Pinellia Ternata with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Evidence from animal research shows that a Pinellia ternata preparation decreases activity and increases sleeping time.

Full Pinellia Ternata + Phenobarbital, Phenytoin answer

Can you take Poria Mushroom with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking poria mushroom extract may enhance the therapeutic and adverse effects of sedatives.

Full Poria Mushroom + Phenobarbital, Phenytoin answer

Can you take Propolis with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2C19.

Full Propolis + Phenobarbital, Phenytoin answer

Can you take Pu-erh Tea with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, pu-erh tea might reduce the effects of phenobarbital and increase the risk for convulsions.

Full Pu-erh Tea + Phenobarbital, Phenytoin answer

Can you take Puravive with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Puravive contains quercetin, which has been shown in studies to mildly inhibit the CYP2C9 metabolizing enzyme.

Full Puravive + Phenobarbital, Phenytoin answer

Can you take Quercetin with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase the levels and adverse effects of CYP2C9 substrates.

Full Quercetin + Phenobarbital, Phenytoin answer

Can you take Rauvolfia Vomitoria with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking Rauvolfia vomitoria might cause additive sedative effects.

Full Rauvolfia Vomitoria + Phenobarbital, Phenytoin answer

Can you take Rauwolscine with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking rauwolscine with seizure threshold lowering drugs might increase the risk of adverse convulsant effects.

Full Rauwolscine + Phenobarbital, Phenytoin answer

Can you take Red Yeast Rice with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use might increase the risk of liver damage.

Full Red Yeast Rice + Phenobarbital, Phenytoin answer

Can you take Resveratrol with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, resveratrol might increase levels of drugs metabolized by CYP2C19.

Full Resveratrol + Phenobarbital, Phenytoin answer

Can you take Rhubarb with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of rhubarb with potentially hepatotoxic drugs might increase the risk of developing liver damage.

Full Rhubarb + Phenobarbital, Phenytoin answer

Can you take Rooibos with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking rooibos with CYP2C19 substrates may increase the effects of CYP2C19 substrates.

Full Rooibos + Phenobarbital, Phenytoin answer

Can you take Saffron with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, concomitant use of saffron and CNS depressants might have additive sedative effects.

Full Saffron + Phenobarbital, Phenytoin answer

Can you take Sage with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, taking sage might increase the sedative and adverse effects of CNS depressants.

Full Sage + Phenobarbital, Phenytoin answer

Can you take Saigon Cinnamon with Phenobarbital, Phenytoin?

Moderate Possibly, but carefully — this moderate-rated combination may need monitoring, a dose adjustment, or separated timing. Theoretically, Saigon cinnamon might cause additive effects when used with hepatotoxic drugs.

Full Saigon Cinnamon + Phenobarbital, Phenytoin answer
Read the list like a pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each entry links to a full report with the clinical detail, likelihood, evidence level, and citations for that exact combination.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

How Does Our Interaction Checker Work?

Behind every verdict on this page is a category system. Our source database doesn’t document supplement interactions drug-by-drug — it documents them against groups of medications that behave the same way (for example, “drugs processed by the CYP3A4 liver enzyme” or “blood-thinning medications”).

So the check works in three steps: (1) Phenobarbital, Phenytoin is classified into the pharmacology categories it belongs to, (2) every supplement interaction documented against any of those categories is inherited by Phenobarbital, Phenytoin, and (3) each ingredient keeps its own severity, likelihood, and evidence grades from the underlying record. That’s why one supplement can carry several records for one drug — it may interact through more than one category.

Phenobarbital, Phenytoin sits in 17 interaction categories. Open any one to see what the group means:

Cns Depressants 78 ingredients

Central-nervous-system depressants. Sedating supplements can intensify drowsiness and slowed reactions when combined.

78 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2C9 (Cyp2C9) Substrates 64 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

64 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Hepatotoxic Drugs 38 ingredients

Medications with known liver considerations. Supplements that can stress the liver add to the load.

38 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2C19 (Cyp2C19) Substrates 33 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

33 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Phenytoin (Dilantin) 23 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

23 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 3A4 (Cyp3A4) Inducers 19 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

19 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Oral Drugs 17 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

17 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Phenobarbital (Luminal) 16 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

16 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Anticonvulsants 15 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

15 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2B6 (Cyp2B6) Substrates 15 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

15 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2C8 (Cyp2C8) Substrates 11 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

11 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Barbiturates 6 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

6 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Seizure Threshold Lowering Drugs 6 ingredients

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

6 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2C9 (Cyp2C9) Inducers 3 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

3 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 2C19 (Cyp2C19) Inducers 2 ingredients

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

2 of the supplement ingredients on this page reach Phenobarbital, Phenytoin through this category.

Cytochrome P450 1A2 (Cyp1A2) Inducers 1 ingredient

A drug-metabolism group: these medications are processed by the named liver enzyme (a cytochrome P450). Supplements that speed this enzyme up or slow it down can lower or raise the medication's levels in your body.

1 of the supplement ingredient on this page reaches Phenobarbital, Phenytoin through this category.

Phenytoin (Dilantin) 1 ingredient

A pharmacology grouping from our source database: medications in this group share a property that certain supplements are known to interact with, so an interaction documented for the group applies to every drug in it.

1 of the supplement ingredient on this page reaches Phenobarbital, Phenytoin through this category.

Related: does Phenobarbital, Phenytoin deplete any nutrients?

Phenobarbital, Phenytoin has 23 reported nutrient associations in the research literature — see the Phenobarbital, Phenytoin nutrient depletion report.

Check a real product

Take a Supplement Product? Check the Whole Bottle Against Phenobarbital, Phenytoin

Most supplements are combination products — and the interaction may come from an ingredient you didn’t buy it for. Search any product below (or scan its label) and we’ll check every ingredient on it against Phenobarbital, Phenytoin.

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Pharmacist Counseling Corner

Phenobarbital, Phenytoin & Supplements: Common Questions

What supplements interact with Phenobarbital, Phenytoin?
More than you might expect — 229 in total, though they are far from equal: 9 are rated major, 192 moderate, and 28 minor. The ranked list on this page puts the ones that genuinely matter first, and every entry opens a full report on that exact pair. The highest-ranked right now: Beer, Siberian Cocklebur, St. John's Wort.
Which Phenobarbital, Phenytoin supplement interactions are the most serious?
The 9 major-rated combinations — led by Beer, Siberian Cocklebur, St. John's Wort, Wine and 1,4-butanediol — deserve real caution: these are the ones generally best avoided, or used only with your prescriber watching. If you take any of them today, don't panic and don't stop anything abruptly — call your pharmacist first. Jump to the ranked list.
Can I take vitamins or supplements while on Phenobarbital, Phenytoin?
Usually yes — most people on Phenobarbital, Phenytoin can take most supplements. The catch is the exceptions, and they aren't always the exotic ones (St. John's Wort trips up more prescriptions than almost anything sold next to it). Look up each ingredient you actually take in the list above, and treat "no known interaction" as a green-ish light, not a guarantee. Try the label scanner or the interaction checker.
Do brands like Dilantin with PB have the same supplement interactions as Phenobarbital, Phenytoin?
Yes — Dilantin with PB all contain Phenobarbital, Phenytoin, so everything on this page applies to them equally. Interactions belong to the active drug, never to the brand on the box; the same is true of generics.
Where do these interaction ratings come from?
Every rating comes from the Natural Medicines database — the same evidence-graded reference pharmacists and hospitals use — and each interaction carries three separate grades: severity (how bad it can be), likelihood (how well it's documented in studies and case reports), and an evidence level. Our pharmacists review the content; we never let an AI decide an interaction. See how to read the ratings and our editorial policy.
Does Phenobarbital, Phenytoin deplete any vitamins or nutrients?
It might — Phenobarbital, Phenytoin has 23 reported nutrient-depletion associations in the research literature, which is a different question from interactions: instead of a supplement changing the drug, the drug may lower a nutrient over time. See the Phenobarbital, Phenytoin nutrient depletion report for the specifics and what to discuss with your pharmacist.
What about Phenobarbital, Phenytoin and my other medications?
This page covers Phenobarbital, Phenytoin against supplements and herbal ingredients. Checking Phenobarbital, Phenytoin against your other prescription or OTC medications is a different tool — our drug interaction checker covers that side. Head to the drug–drug interaction checker.

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

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Sourcing

Where This Data Comes From — and Why You Can Trust It

🧪 Licensed clinical database

Every interaction verdict on this page comes from Natural Medicines Pro (TRC Healthcare / Therapeutic Research) — the same evidence-graded reference used by pharmacists and hospitals. We license this data directly; we do not scrape it, and no AI invents an interaction.

🧑‍⚕️ Pharmacist review

This page is curated and coded by , Clinical Pharmacist, with additional analysis by the HelloPharmacist Pharmacist Team. Editorial commentary is ours; the licensed interaction records are shown as sourced.

🔄 Kept current

Our interaction database refreshes on a weekly cycle, and this page re-checks the live database every time it’s rebuilt — what you see reflects the database as of October 1, 2026.

🔍 Full transparency

How every dataset on this site is sourced, licensed, and updated is documented publicly: our data sources · editorial policy · how we use AI.

Educational information, not medical advice. An interaction being on file does not mean it will happen to you — and absence of one is not proof of safety. Never start or stop a medication or supplement without talking to your pharmacist or doctor.