Drug & supplement interaction

Black Hellebore + Quinine

Quinine brand name: Qualaquin.

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

Black Hellebore has a moderate interaction with Quinine. Theoretically, concomitant use of quinine and black hellebore can increase the risk of cardiac glycoside toxicity.

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

Black Hellebore and Quinine

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

Moderate

QUININE

Theoretically, concomitant use of quinine and black hellebore can increase the risk of cardiac glycoside toxicity.
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 short version: Black Hellebore should not be taken as a supplement at all. It contains naturally toxic, heart-active compounds that behave a lot like digoxin and other cardiac glycosides, and they can throw off your heart rhythm even in small amounts.

Now add quinine to the picture. Quinine can affect the heart's electrical timing on its own, and it's known to raise blood levels of digoxin-type compounds. So in theory, pairing it with Black Hellebore could stack two heart-affecting effects, raising the risk of dangerous, irregular heartbeats, nausea, vision changes, or ringing in the ears. This warning is based on pharmacology, not real cases, but the toxicity of this plant makes it not worth the gamble. Please check with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Burnham TH, ed. Drug Facts and Comparisons, Updated Monthly. Facts and Comparisons, St. Louis, MO.

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

Black Hellebore Also Interacts With Other Medications

Black Hellebore has 132 moderate known drug interactions in our database — the Quinine one above is one of them. If you take anything else, check it against the full list below.

Moderate 132 No known interaction 2,698 (incl. Quinine)
Taking anything else?

Check Another of Your Medications Against Black Hellebore

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

From our Q&A

Questions About Black Hellebore or Quinine

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

This page covers Black Hellebore only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Quinine page lists 175 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Cinchona (major), Foxglove (major), Grapefruit (major) and Lily-of-the-valley (major).

By severity: 9 major · 125 moderate · 41 minor.

From our pharmacist’s overview on the Quinine page

“Quinine (Qualaquin) earns a genuine pause before you add any supplement, because nine of its 175 interacting ingredients are rated major, and two are as everyday as grapefruit and St. John's wort.”

Reviewed by 2 · Jul 18, 2026

Open the Quinine interaction page

One more smart check

Taking Black Hellebore as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1 real supplement products containing Black Hellebore, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Black Hellebore. Your product may carry other ingredients that interact with Quinine too, on top of Black Hellebore — 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 Black Hellebore and Quinine 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 Black Hellebore
Top half

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

29 days ago today
Medication Quinine
Steady interest

#2,182 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 Black Hellebore

What is Black Hellebore?

Black Hellebore
  • Constipation (historical purgative)
  • Mental and nervous disorders (historical)
  • Worm and parasite expulsion (historical)
  • Fluid retention (historical)
  • Heart conditions (historical, dangerous)

Black Hellebore is a highly toxic plant that was used in old folk medicine but has no proven, safe modern use. Because even small amounts can cause severe poisoning and dangerous heart rhythm problems, it should not be taken as a supplement. Talk to a doctor or pharmacist before considering any product that contains it.

Read the full Black Hellebore monograph & all interactions
Medication

About Quinine

What Is Quinine Used For?

Brand name: Qualaquin

Quinine sulfate capsules (brands Qualaquin and Quinine Sulfate) are approved to treat uncomplicated Plasmodium falciparum malaria in adults. This includes strains of malaria that have become resistant to chloroquine.

Quinine sulfate capsules are not approved for severe or complicated malaria, for preventing malaria, or for treating or preventing nocturnal leg cramps. Using them for leg cramps carries serious risks that outweigh any potential benefit.

See full Quinine drug information
Keep checking

Other Drugs & Black Hellebore

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

0Major
132Moderate
0Minor
2,697No known interaction
132 Moderate 2,697 No interaction
Moderate

132 interactions

Showing 60 of 132 moderate interactions — see all 132 on the Black Hellebore page.

No interaction 2,697 drugs checked — show the list

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

Showing the 60 most looked-up of 2,697 medications checked with no known interaction — see the full Black Hellebore list.

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

Can you take Black Hellebore with Quinine?
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 Black Hellebore and Quinine 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 Quinine and Black Hellebore?

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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.