Drug & supplement interaction

European Mistletoe + Guanabenz Acetate

Guanabenz Acetate brand name: Wytensin.

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

European Mistletoe has a moderate interaction with Guanabenz Acetate. Theoretically, European mistletoe might increase the risk of hypotension when taken with antihypertensive drugs.

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

European Mistletoe and Guanabenz Acetate

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Guanabenz Acetate

Guanabenz Acetate falls under ANTIHYPERTENSIVE DRUGS — the group European Mistletoe interacts with.

Theoretically, European mistletoe might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that European mistletoe extracts have hypotensive 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 simple version: guanabenz already lowers your blood pressure by calming the signals that speed up your heart and tighten your blood vessels. Some animal studies hint that European mistletoe extracts may nudge blood pressure down too. So in theory, pairing the two could add up and drop your pressure a little more than expected.

If that happened, you might notice feeling dizzy or lightheaded, tired, or faint when you stand up quickly. I want to be honest, though: this concern comes mostly from lab and animal research, not strong human studies, so it's more of a theoretical caution than a proven problem. Mistletoe should only be used under medical supervision anyway. Please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Nazaruk J, Orlikowski P. Phytochemical profile and therapeutic potential of Viscum album L. Nat Prod Res. 2016;30(4):373-85.
  2. Khan T, Ali S, Qayyum R, Hussain I, Wahid F, Shah AJ. Intestinal and vascular smooth muscle relaxant effect of Viscum album explains its medicinal use in hyperactive gut disorders and hypertension. BMC Complement Altern Med. 2016 Jul 27;16:251. PubMed

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 Mistletoe Also Interacts With Other Medications

European Mistletoe has 292 moderate known drug interactions in our database — the Guanabenz Acetate one above is one of them. If you take anything else, check it against the full list below.

Moderate 292 No known interaction 2,538 (incl. Guanabenz Acetate)
Taking anything else?

Check Another of Your Medications Against European Mistletoe

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

Everything else you take

See Every Supplement That Interacts With Guanabenz Acetate

This page covers European Mistletoe only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Guanabenz Acetate page lists 137 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 21 minor.

From our pharmacist’s overview on the Guanabenz Acetate page

“Guanabenz acetate (Wytensin) is an older blood pressure medicine, and the 137 supplements on file call for genuine vigilance, beginning with the four rated major. Two are toxic plants that can strain the heart or swing pressure hard, one is tyramine, found in aged cheeses and cured meats, which fights the drug's effect, and one is acti…”

Reviewed by 2 · Jul 18, 2026

Open the Guanabenz Acetate interaction page

One more smart check

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

We hold 91 real supplement products containing European Mistletoe, each one broken down to its full ingredient list — and combination products often carry several ingredients besides European Mistletoe. Your product may carry other ingredients that interact with Guanabenz Acetate too, on top of European Mistletoe — 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 European Mistletoe and Guanabenz Acetate 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 Mistletoe
Steady interest

#1,080 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Guanabenz Acetate
Steady interest

#2,073 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 Mistletoe

What is European Mistletoe?

European Mistletoe
  • Cancer supportive care
  • Immune support
  • High blood pressure
  • Anxiety and stress
  • Inflammation

European mistletoe is a parasitic plant most studied as an injectable extract used alongside conventional cancer care in some European countries, mainly to improve quality of life rather than to cure cancer. The plant is toxic if eaten, and oral or self-treatment can be dangerous, so it should only be used under medical supervision. Talk to your pharmacist or doctor before using any mistletoe product.

Read the full European Mistletoe monograph & all interactions
Medication

About Guanabenz

What Is Guanabenz Used For?

Brand name: Wytensin

  • Guanabenz is used to treat high blood pressure. It is in a class of medications called centrally acting alpha2A-adrenergic receptor agonists. Guanabenz works by decreasing your heart rate and relaxing the blood vessels so that blood can flow more easily through the body.

  • High blood pressure is a common condition and when not treated, can cause damage to the brain, heart, blood vessels, kidneys and other parts of the body. Damage to these organs may cause heart disease, a heart attack, heart failure, stroke, kidney failure, loss of vision, and other problems. In addition to taking medication, making lifestyle changes will also help to control your blood pressure. These changes include eating a diet that is low in fat and salt, maintaining a healthy weight, exercising at least 30 minutes most days, not smoking, and using alcohol in moderation.

See full Guanabenz drug information
Keep checking

Other Drugs & European Mistletoe

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

0Major
292Moderate
0Minor
2,537No known interaction
292 Moderate 2,537 No interaction
Moderate

292 interactions

Showing 60 of 292 moderate interactions — see all 292 on the European Mistletoe page.

No interaction 2,537 drugs checked — show the list

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

Showing the 60 most looked-up of 2,537 medications checked with no known interaction — see the full European Mistletoe list.

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

Can you take European Mistletoe with Guanabenz Acetate?
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 European Mistletoe and Guanabenz Acetate 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 Guanabenz Acetate and European Mistletoe?

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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.