Drug & supplement interaction

European Mandrake + Clemastine

Clemastine brand name: Tavist Allergy.

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

Clemastine falls into 2 drug categories that European Mandrake can interact with; the most serious is rated moderate. Theoretically, concurrent use might increase absorption of some drugs because of inhibited gastrointestinal (GI) motility caused by European mandrake.

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

European Mandrake and Clemastine

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

Why Are There 2 Interactions?

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

Moderate

ORAL DRUGS

1 of 2

Why this applies to Clemastine

Clemastine falls under ORAL DRUGS — the group European Mandrake interacts with.

Theoretically, concurrent use might increase absorption of some drugs because of inhibited gastrointestinal (GI) motility caused by European mandrake.
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

First, a real safety note: European mandrake is genuinely poisonous, and we don't recommend taking it in any form. But here's the specific concern with clemastine (Tavist). Mandrake's natural chemicals, like atropine and scopolamine, slow down how fast your gut moves. The thinking is that a slower gut could let more clemastine get absorbed, nudging its levels higher.

That matters because clemastine is itself a sedating antihistamine with its own drying effects. Stacking it on top of mandrake could pile on extra drowsiness, dry mouth, blurred vision, constipation, trouble urinating, and a faster heartbeat. This warning is theoretical, based on how these substances behave, not on real cases. Still, please skip the mandrake and talk with your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
Moderate

ANTICHOLINERGIC DRUGS

2 of 2

Clemastine also falls under ANTICHOLINERGIC DRUGS.

Concurrent use may cause additive anticholinergic effects and adverse effects. Anticholinergic drugs include conventional medications containing tropane alkaloids such as atropine, as well as phenothiazines, amantadine, some antiparkinson drugs, glutethimide, meperidine, tricyclic antidepressants, antiarrhythmic agents, and antihistamines.
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 is the simple version: clemastine (Tavist) is an older antihistamine that already has a fair amount of anticholinergic activity. That means it can dry you out and slow certain body functions on its own. European mandrake is loaded with the same kind of chemicals (atropine, scopolamine, hyoscyamine), so pairing the two would stack these effects on top of each other.

Realistically, you could see worse dry mouth, blurred vision, constipation, trouble urinating, a faster heartbeat, confusion, and heavy drowsiness. This concern is based on how these compounds work rather than on hard studies, so it is theoretical. Still, mandrake is genuinely toxic and we never recommend taking it. Please don't combine them, and check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 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

European Mandrake Also Interacts With Other Medications

European Mandrake has 2,041 moderate known drug interactions in our database — the Clemastine one above is among them. If you take anything else, check it against the full list below.

Moderate 2,041 No known interaction 789 (incl. Clemastine)
Taking anything else?

Check Another of Your Medications Against European Mandrake

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

From our Q&A

Questions About European Mandrake or Clemastine

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

This page covers European Mandrake only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clemastine page lists 72 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Scopolia (major), Alfalfa (moderate) and Angel's Trumpet (moderate).

By severity: 3 major · 57 moderate · 12 minor.

From our pharmacist’s overview on the Clemastine page

“Clemastine (Tavist Allergy) is an older, sedating antihistamine that already dries the mouth, blurs vision, and slows the gut, and that is exactly why this list earns real caution rather than a quick skim. Thirty of the 72 supplements on file pile the same drying, sedating anticholinergic load on top, and two of the three major-rated e…”

Reviewed by 2 · Jul 18, 2026

Open the Clemastine interaction page

How much people look this up

Where European Mandrake and Clemastine 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 European Mandrake
Top 25%

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

29 days ago today
Medication Clemastine
Steady interest

#2,068 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 European Mandrake

What is European Mandrake?

European Mandrake
  • Insomnia (traditional)
  • Pain relief (historical)
  • Anxiety or depression (folk use)
  • Gout and aches (traditional)
  • Sedation or anesthesia (historical)

European mandrake is a highly toxic plant from the nightshade family that was used in ancient and medieval times as a sedative and pain reliever. It contains powerful poisons that can cause serious harm or death, and there is no proof it safely treats any condition. We strongly recommend you do not consume mandrake in any form.

Read the full European Mandrake monograph & all interactions
Medication

About Clemastine

What Is Clemastine Used For?

Brand name: Tavist Allergy

Clemastine treats symptoms of allergic rhinitis (hay fever and similar nasal allergies) — including sneezing, runny nose, itching, and watery eyes. The oral solution (Clemastine Fumarate syrup) is indicated for adults and children aged 6 through 12 years. The tablets (Clemastine Fumarate and Clemsza) are indicated for adults.

Clemastine also treats mild, uncomplicated allergic skin reactions — specifically urticaria (hives) and angioedema (swelling under the skin) — at the appropriate dosage level, in both the oral solution and tablet forms.

See full Clemastine drug information
Keep checking

Other Drugs & European Mandrake

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

0Major
2,041Moderate
0Minor
788No known interaction
2,041 Moderate 788 No interaction
Moderate

2,041 interactions

Showing 60 of 2,041 moderate interactions — see all 2,041 on the European Mandrake page.

No interaction 788 drugs checked — show the list

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

Showing the 60 most looked-up of 788 medications checked with no known interaction — see the full European Mandrake list.

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

Can you take European Mandrake with Clemastine?
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 European Mandrake and Clemastine?
Clemastine belongs to more than one drug category, and European Mandrake 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 European Mandrake and Clemastine 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 Clemastine and European Mandrake?

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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.