Drug & supplement interaction

Wormwood + Phenobarbital

Phenobarbital brand names: Phenobarbital, Solfoton, Luminal.

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

Wormwood has a moderate interaction with Phenobarbital. Theoretically, taking wormwood might interfere with the effects of anticonvulsant drugs.

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

Wormwood and Phenobarbital

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

Moderate

ANTICONVULSANTS

Why this applies to Phenobarbital

Phenobarbital falls under ANTICONVULSANTS — the group Wormwood interacts with.

Theoretically, taking wormwood might interfere with the effects of anticonvulsant drugs.
Thujone, a constituent of wormwood, has convulsant 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 concern with pairing wormwood and phenobarbital. Phenobarbital works by calming overactive brain signals to keep seizures under control. Wormwood contains a compound called thujone, which in larger amounts can actually do the opposite and make the brain more prone to seizures. So in theory, wormwood could work against what your phenobarbital is trying to do, and that might mean less seizure protection.

I want to be honest about how strong this evidence is: it's mostly based on lab and animal findings, not solid human studies, so it's a theoretical worry rather than something we see often. Still, since seizure control is too important to gamble with, I'd skip wormwood supplements while you're on phenobarbital unless your doctor or pharmacist tells you otherwise.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hold KM, Sirisoma NS, Casida JE. Detoxification of alpha- and beta-Thujones (the active ingredients of absinthe): site specificity and species differences in cytochrome P450 oxidation in vitro and in vivo. Chem Res Toxicol 2001;14:589-95.

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

Wormwood Also Interacts With Other Medications

Wormwood has 49 moderate known drug interactions in our database — the Phenobarbital one above is one of them. If you take anything else, check it against the full list below.

Moderate 49 No known interaction 2,781 (incl. Phenobarbital)
Taking anything else?

Check Another of Your Medications Against Wormwood

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

From our Q&A

Questions About Wormwood or Phenobarbital

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

This page covers Wormwood only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Phenobarbital page lists 174 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 Henbane (major).

By severity: 10 major · 143 moderate · 21 minor.

Open the Phenobarbital interaction page

One more smart check

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

We hold 387 real supplement products containing Wormwood, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Wormwood. Your product may carry other ingredients that interact with Phenobarbital too, on top of Wormwood — 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 Wormwood and Phenobarbital 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 Wormwood
Top 25%

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

29 days ago today
Medication Phenobarbital
Top half

#1,135 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 Wormwood

What is Wormwood?

Wormwood
  • Digestive upset and poor appetite
  • Intestinal parasites
  • Crohn's disease symptoms
  • Bitter tonic for indigestion
  • Flavoring in absinthe and vermouth

Wormwood is a very bitter herb traditionally used to stimulate appetite and ease digestion, and it has early research interest in Crohn's disease. It contains thujone, which can be toxic in large amounts, so it should only be used short-term in controlled doses. Talk to a pharmacist or doctor before using it, and avoid it if you are pregnant or breastfeeding.

Read the full Wormwood monograph & all interactions
Medication

About Phenobarbital

What Is Phenobarbital Used For?

Brand names: Phenobarbital, Solfoton, Luminal

Phenobarbital tablets and oral solutions are used to treat generalized and partial seizures and as a sedative. Phenobarbital Sodium injection is used as a long-term anticonvulsant for generalized tonic-clonic and focal seizures, for emergency control of acute convulsive episodes (including status epilepticus), for sedation, short-term treatment of insomnia, and as a preanesthetic. It is also used in pediatric patients as an anticonvulsant and sedative, including before and after surgery.

Sezaby (phenobarbital injection, intravenous) is specifically indicated for the treatment of neonatal seizures in term and preterm infants. It is not approved for use in adolescents or adults.

See full Phenobarbital drug information
Keep checking

Other Drugs & Wormwood

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

0Major
49Moderate
0Minor
2,780No known interaction
49 Moderate 2,780 No interaction
Moderate

49 interactions

No interaction 2,780 drugs checked — show the list

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

Showing the 60 most looked-up of 2,780 medications checked with no known interaction — see the full Wormwood list.

See the full Wormwood interactions page
See every supplement checked against Phenobarbital, 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
Wormwood monograph › Uses, safety, and every drug interaction in one place Phenobarbital supplement interactions › Every supplement checked against Phenobarbital, ranked by severity Phenobarbital 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 Wormwood and Phenobarbital Together: Common Questions

Can you take Wormwood with Phenobarbital?
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 Wormwood and Phenobarbital 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 Phenobarbital and Wormwood?

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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.