Drug & supplement interaction

Cinchona + Quinine

Quinine brand name: Qualaquin.

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

Cinchona has a major interaction with Quinine. Theoretically, taking cinchona might increase plasma levels and adverse effects of quinine.

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

Cinchona and Quinine

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

Major

QUININE

Theoretically, taking cinchona might increase plasma levels and adverse effects of quinine.
Cinchona contains quinine.
Severity Major 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

Here's the simple version: cinchona bark is basically nature's raw source of quinine. So if you're already taking prescription quinine (Qualaquin) and then add cinchona on top, you're really just stacking more quinine into your body. That can push your quinine levels higher than intended.

Too much quinine can cause a cluster of symptoms doctors call cinchonism, things like ringing in the ears, headache, nausea, dizziness, and blurred vision. At higher levels it can also affect your heart rhythm and blood cells, which is why this combo is flagged as a major concern. The bark isn't standardized, so you can't predict how much extra quinine you're getting. This warning is based on pharmacology rather than formal studies, but the logic is solid. Please don't combine these without checking with your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.

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

Cinchona Also Interacts With Other Medications

Cinchona has 2 major, 473 moderate, 16 minor 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.

Major 2 Moderate 473 Minor 16 No known interaction 2,339 (incl. Quinine)
Taking anything else?

Check Another of Your Medications Against Cinchona

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

From our Q&A

Questions About Cinchona 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 Cinchona 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 Cinchona 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), Foxglove (major), Grapefruit (major), Lily-of-the-valley (major) and Oleander (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 Cinchona as Part of a Dietary Supplement Product? Check It for Interactions

We hold 12 real supplement products containing Cinchona, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cinchona. Your product may carry other ingredients that interact with Quinine too, on top of Cinchona — 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 Cinchona 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 Cinchona
Steady interest

#925 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 Cinchona

What is Cinchona?

Cinchona
  • Malaria (historical/traditional)
  • Fever
  • Leg cramps and restless legs
  • Digestive upset and loss of appetite
  • Bitter tonic

Cinchona bark is the natural source of quinine and has been used for centuries to treat malaria and fever, but the bark itself is not standardized and can be unpredictable and risky. Modern medicine uses purified, dose-controlled quinine instead, and the supplement form carries real dangers, including serious heart and blood problems. Talk to a pharmacist or doctor before using it, and avoid it during pregnancy.

Read the full Cinchona 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 & Cinchona

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

2Major
473Moderate
16Minor
2,338No known interaction
2 Major 473 Moderate 16 Minor 2,338 No interaction
Major

2 interactions

Moderate

473 interactions

Showing 60 of 473 moderate interactions — see all 473 on the Cinchona page.

Minor

16 interactions

No interaction 2,338 drugs checked — show the list

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

Showing the 60 most looked-up of 2,338 medications checked with no known interaction — see the full Cinchona list.

See the full Cinchona 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
Cinchona 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 Cinchona and Quinine Together: Common Questions

Can you take Cinchona with Quinine?
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 Cinchona and Quinine 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 Quinine and Cinchona?

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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.