Drug & supplement interaction

Yerba Mansa + 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

Yerba Mansa has a moderate interaction with Phenytoin. Theoretically, concomitant use might cause additive or prolonged sedative effects.

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

Yerba Mansa and Phenytoin

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

Moderate

CNS DEPRESSANTS

Why this applies to Phenytoin

Phenytoin falls under CNS DEPRESSANTS — the group Yerba Mansa interacts with.

Theoretically, concomitant use might cause additive or prolonged sedative effects.
Severity Moderate Likelihood Probable Evidence D

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..

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

Here's the simple version: phenytoin (Dilantin) can already make some people feel drowsy, foggy, or unsteady on their feet. Yerba mansa may have mild calming, sedative-type effects of its own. Put the two together and the worry is that those tired, sleepy, or off-balance feelings could stack up a bit more than usual.

I want to be honest about how strong this concern is. It is theoretical, based on how these compounds behave rather than real cases in people, so it may never amount to much. Still, phenytoin is a finicky drug with a narrow safety window, so I'd play it safe. Before combining them, check with your pharmacist or doctor, and watch for extra drowsiness or dizziness if you do.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

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

Yerba Mansa Also Interacts With Other Medications

Yerba Mansa has 247 moderate 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.

Moderate 247 No known interaction 2,583 (incl. Phenytoin)
Taking anything else?

Check Another of Your Medications Against Yerba Mansa

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

From our Q&A

Questions About Yerba Mansa 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 Yerba Mansa 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 Yerba Mansa 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 Yerba Mansa as Part of a Dietary Supplement Product? Check It for Interactions

We hold 139 real supplement products containing Yerba Mansa, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Yerba Mansa. Your product may carry other ingredients that interact with Phenytoin too, on top of Yerba Mansa — 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 Yerba Mansa 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 Yerba Mansa
Top half

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

29 days ago today
Medication Phenytoin
Steady interest

#1,724 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 Yerba Mansa

What is Yerba Mansa?

Yerba Mansa
  • Sore throat and respiratory congestion
  • Skin irritation and wounds
  • Mouth and gum inflammation
  • Urinary and digestive complaints
  • Antimicrobial support

Yerba mansa is a traditional Southwestern and Mexican medicinal plant used for sore throats, skin problems, and infections. Modern scientific evidence in humans is very limited, so its effectiveness is largely unproven. If you want to try it, talk to a pharmacist or doctor first, and avoid it during pregnancy and breastfeeding.

Read the full Yerba Mansa 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 & Yerba Mansa

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

0Major
247Moderate
0Minor
2,582No known interaction
247 Moderate 2,582 No interaction
Moderate

247 interactions

Showing 60 of 247 moderate interactions — see all 247 on the Yerba Mansa page.

No interaction 2,582 drugs checked — show the list

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

Showing the 60 most looked-up of 2,582 medications checked with no known interaction — see the full Yerba Mansa list.

See the full Yerba Mansa 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
Yerba Mansa 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 Yerba Mansa and Phenytoin Together: Common Questions

Can you take Yerba Mansa 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.
How serious is the Yerba Mansa 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 Yerba Mansa?

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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.