Drug & supplement interaction

American Mistletoe + Nimodipine

Nimodipine brand names: Nimotop, Nymalize.

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

American Mistletoe has a major interaction with Nimodipine. American mistletoe contains phoratoxin, a compound toxic to humans that induces smooth muscle contraction and vasoconstriction, potentially increasing blood pressure and heart rate.

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

American Mistletoe and Nimodipine

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

Major

Antihypertensive Drugs

Why this applies to Nimodipine

Nimodipine falls under Antihypertensive Drugs — the group American Mistletoe interacts with.

American mistletoe contains phoratoxin, a compound toxic to humans that induces smooth muscle contraction and vasoconstriction, potentially increasing blood pressure and heart rate. Case reports of cardiotoxicity have been documented with American mistletoe, and it should not be used with antihypertensive drugs or by individuals with cardiac conditions. American mistletoe is uncommon in dietary supplements, and formulations containing it are generally homeopathic. European mistletoe, which lacks phoratoxin, is more commonly used.
Severity Major Likelihood Probable Evidence C

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

Nimodipine is a calcium channel blocker that works by relaxing and widening blood vessels in the brain after a bleed. American mistletoe pulls in the opposite direction. Its toxin, phoratoxin, can tighten blood vessels and bump up blood pressure and heart rate. So instead of adding to nimodipine's job, mistletoe may fight against it and could blunt the very effect you are counting on after a brain bleed.

On top of that, mistletoe has been linked to heart toxicity in case reports, which is a real concern with a serious medication like this. Honestly, American mistletoe is toxic and not recommended for anyone, especially someone on nimodipine. Please keep it away from yourself, kids, and pets, and check with your pharmacist or doctor with any questions.

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

American Mistletoe Also Interacts With Other Medications

American Mistletoe has 189 major, known drug interactions in our database — the Nimodipine one above is one of them. If you take anything else, check it against the full list below.

Major 189 No known interaction 2,641 (incl. Nimodipine)
Taking anything else?

Check Another of Your Medications Against American Mistletoe

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

Everything else you take

See Every Supplement That Interacts With Nimodipine

This page covers American Mistletoe only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nimodipine page lists 227 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Grapefruit (major), St. John's Wort (major) and Tyramine (major).

By severity: 6 major · 180 moderate · 41 minor.

From our pharmacist’s overview on the Nimodipine page

“Nimodipine (Nimotop, Nymalize) is given after bleeding around the brain to stop blood vessels from clamping down, and the supplement interactions on file earn real caution, not a shrug. Of the 227 ingredients listed, most either interfere with CYP3A4, the liver enzyme that clears nimodipine, or lower blood pressure on their own and sta…”

Reviewed by 2 · Jul 18, 2026

Open the Nimodipine interaction page

How much people look this up

Where American Mistletoe and Nimodipine 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 American Mistletoe
Steady interest

#1,249 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Nimodipine
Steady interest

#2,226 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 American Mistletoe

What is American Mistletoe?

American Mistletoe
  • Traditional folk remedies
  • Digestive complaints
  • Decorative holiday plant

American mistletoe is a parasitic plant that is best known as a holiday decoration, not a proven medicine. It contains toxins that can harm the heart, gut, and blood vessels, and it has little reliable evidence to support any health use. We do not recommend taking it, and all parts should be kept away from children and pets.

Read the full American Mistletoe monograph & all interactions
Medication

About Nimodipine

What Is Nimodipine Used For?

Brand names: Nimotop, Nymalize

Nimodipine — available as capsules and oral solution — is used to improve neurological outcomes after a subarachnoid hemorrhage (SAH), a type of bleeding that occurs around the brain when an intracranial berry aneurysm ruptures. It works to reduce the incidence and severity of ischemic deficits (areas of the brain damaged by reduced blood flow) that can follow this kind of bleed.

This use applies across nimodipine capsules, nimodipine oral solution, and Nymalize oral solution. It is indicated for adult patients regardless of how severe their neurological condition is at the time treatment begins.

See full Nimodipine drug information
Keep checking

Other Drugs & American Mistletoe

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

189Major
0Moderate
0Minor
2,640No known interaction
189 Major 2,640 No interaction
Major

189 interactions

Showing 60 of 189 major interactions — see all 189 on the American Mistletoe page.

No interaction 2,640 drugs checked — show the list

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

Showing the 60 most looked-up of 2,640 medications checked with no known interaction — see the full American Mistletoe list.

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

Can you take American Mistletoe with Nimodipine?
This is rated a major interaction, so the combination is best avoided unless your doctor or pharmacist has specifically told you otherwise. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the American Mistletoe and Nimodipine interaction?
We rate it Major. This is a clinically significant combination that is generally best avoided, or used only under the direct supervision of your physician or pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Nimodipine and American 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.