Drug & supplement interaction

American Hellebore + Mecamylamine

Mecamylamine brand name: Inversine.

Major Interaction
The bottom line Major

American Hellebore has a major interaction with Mecamylamine. American hellebore can have potent cardiovascular effects due to the toxic steroid ester alkaloids it contains.

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

American Hellebore and Mecamylamine

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

Major

Antihypertensive Drugs

Why this applies to Mecamylamine

Mecamylamine falls under Antihypertensive Drugs — the group American Hellebore interacts with.

American hellebore can have potent cardiovascular effects due to the toxic steroid ester alkaloids it contains. The alkaloids in this plant notably reduce blood pressure even in small doses. Additionally, the alkaloids can exhibit cardiac depressant, bradycardic, and sedative effects. These alkaloids inhibit the inactivation of sodium-ion channels in excitable cells, particularly those regulating cardiac activity. Furthermore, American hellebore's alkaloids induce vasodilation and block beta-adrenergic activity, potentially influencing the effectiveness or side effects of antihypertensive medications (source https://pubmed.ncbi.nlm.nih.gov/5457326/). Patients should exercise caution and consult healthcare professionals before using American hellebore for any reason.
Severity Major Likelihood Likely Evidence A

Well-controlled human studies have demonstrated the likely existence of this interaction.

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

Mecamylamine (Inversine) is a strong blood pressure medicine that works by blocking nerve signals, and it can already drop your blood pressure quite a bit, sometimes causing dizziness, lightheadedness, or even fainting when you stand up. American Hellebore lowers blood pressure too, and it also slows the heart and acts as a heart depressant. Put together, these two can stack their effects and push your pressure and heart rate dangerously low.

This is a major, well-documented concern. American Hellebore is genuinely poisonous, so I would not pair it with Mecamylamine. If you are even considering any product containing it, please talk with your doctor or pharmacist first.

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 Hellebore Also Interacts With Other Medications

American Hellebore has 327 major, known drug interactions in our database — the Mecamylamine one above is one of them. If you take anything else, check it against the full list below.

Taking anything else?

Check Another of Your Medications Against American Hellebore

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

Everything else you take

See Every Supplement That Interacts With Mecamylamine

This page covers American Hellebore only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Mecamylamine page lists 136 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 4 major · 111 moderate · 21 minor.

From our pharmacist’s overview on the Mecamylamine page

“Mecamylamine (Inversine) is a potent blood pressure medicine, and its interaction list warrants real vigilance, since 119 of the 136 ingredients on file affect blood pressure themselves. Most add to the drug's effect and can drop pressure too far, fish oil among them, while a few push the other way.”

Reviewed by 2 · Jul 18, 2026

Open the Mecamylamine interaction page

How much people look this up

Where American Hellebore and Mecamylamine 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 Hellebore
Steady interest

#1,093 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Mecamylamine
Steady interest

#2,493 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 Hellebore

What is American Hellebore?

American Hellebore
  • High blood pressure
  • Slowing heart rate
  • Toxemia of pregnancy (historical)
  • Convulsions (historical)
  • Pain relief (traditional)

American Hellebore (Veratrum viride) is a highly poisonous plant whose root contains toxic alkaloids that can cause dangerous drops in heart rate and blood pressure, even in small amounts. It is not a safe self-care supplement, and any non-homeopathic product carries a serious risk of poisoning. Do not use it without medical supervision, and talk to a pharmacist or doctor before considering any product that contains it.

Read the full American Hellebore monograph & all interactions
Keep checking

Other Drugs & American Hellebore

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

327Major
0Moderate
0Minor
2,502No known interaction
Major

327 interactions

Showing 60 of 327 major interactions — see all 327 on the American Hellebore page.

No interaction 2,502 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking American Hellebore and Mecamylamine Together: Common Questions

Can you take American Hellebore with Mecamylamine?
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 Hellebore and Mecamylamine 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

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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.