Drug & supplement interaction

Andiroba + Phenytoin

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

Minor Interaction
Medically reviewed by · Updated February 2024
The bottom line Minor

Andiroba has a minor interaction with Phenytoin. Andiroba contains fatty acid amides that have shown potential anticonvulsant effects in animal studies.

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

Andiroba and Phenytoin

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

Minor

Anticonvulsants

Why this applies to Phenytoin

Phenytoin falls under Anticonvulsants — the group Andiroba interacts with.

Andiroba contains fatty acid amides that have shown potential anticonvulsant effects in animal studies. These compounds are believed to act as agonists at gamma-aminobutyric acid (GABA)-A receptors, similar to some anticonvulsant medications. There is a theoretical possibility that combining andiroba with anticonvulsants that also act on GABA receptors could enhance their effects, potentially leading to increased side effects (source: https://pubmed.ncbi.nlm.nih.gov/32164340). However, it's important to note that this is based on theoretical considerations, and more studies are needed to understand the actual interaction between andiroba and anticonvulsants in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the honest picture with andiroba and phenytoin: it's mostly theoretical. Some compounds in andiroba may gently nudge the same calming brain receptors (GABA) that certain seizure medicines work on. The thought is that, in very large amounts taken internally, this could add to phenytoin's effects and possibly bring on more drowsiness, dizziness, unsteadiness, or trouble concentrating.

But this idea comes only from animal and lab work, not from real people, and our records grade it as minor and unlikely. Andiroba is also used mainly on the skin, where this kind of effect is very improbable. Phenytoin is a finicky drug where small changes can matter, so before using andiroba internally, please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction

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

Andiroba Also Interacts With Other Medications

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

Minor 49 No known interaction 2,781 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against Andiroba

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

From our Q&A

Questions About Andiroba 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 Andiroba 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 Andiroba 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 Andiroba 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 Andiroba
Steady interest

#1,447 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Phenytoin
Steady interest

#1,761 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 Andiroba

What is Andiroba?

Andiroba
  • Skin care and wound healing
  • Insect repellent
  • Muscle and joint aches
  • Anti-inflammatory skin conditions
  • Hair and scalp care

Andiroba is an oil pressed from the seeds of an Amazonian tree, used mainly on the skin for inflammation, minor wounds, aches, and as an insect repellent. Most evidence comes from laboratory and animal studies, so its benefits in people are not well proven. It is most often used topically; avoid internal use and use during pregnancy or breastfeeding because safety has not been established.

Read the full Andiroba 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 & Andiroba

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

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

49 interactions

No interaction 2,780 drugs checked — show the list

We also checked Andiroba 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 Andiroba list.

See the full Andiroba 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
Andiroba 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 Andiroba and Phenytoin Together: Common Questions

Can you take Andiroba with 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.
How serious is the Andiroba and 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 Phenytoin and Andiroba?

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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.