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Dietary supplement

Quina Ingredients & Drug Interactions

by Hawaii Pharm

Quina label
See full label image
Liquid Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Quina against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Quina is a dietary supplement by Hawaii Pharm with 1 active ingredient. Its ingredients are commonly taken for malaria (historical/traditional), fever, leg cramps and restless legs.Based on those ingredients, 492 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Quina Bark Extract, Dry. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Quina by Hawaii Pharm

Ask about any prescription or over-the-counter medication and we check it for interactions with Quina by Hawaii Pharm — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Quina by Hawaii Pharm

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

Quina is a liquid extract containing one active ingredient: quina bark extract (dry form). The bark is a natural source of the alkaloids quinine and quinidine.

The product also contains alcohol, water, and glycerin as inactive ingredients that help preserve and formulate the liquid.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Cinchona's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: fever and digestive health tonic.
  • We looked for evidence on: Influenza, Leg cramps, Malaria, Muscle cramps, appetite stimulation, bitter tonic effect — and 1 related terms.
  • The closest evidence on file: Cinchona is rated "Insufficient Reliable Evidence To Rate" for Influenza (Natural Medicines).
  • Also on file: Cinchona is rated "Insufficient Reliable Evidence To Rate" for Malaria, Muscle cramps, Leg cramps.

The evidence for quina bark isn't established in our data. The product is marketed for muscle cramps, cancer, respiratory tract infections, hemorrhoids, influenza, and malaria—but for each of these uses, the effectiveness rating is insufficient reliable evidence to rate.

That means the studies aren't yet robust enough to say whether it works.

The evidence, ingredient by ingredient Cinchona

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Quina carries significant safety cautions. The bark is not dose-controlled, and prolonged use of high doses can cause serious side effects.

Common side effects from oral use include diarrhea, nausea, ringing in the ears, and vomiting. Rare but serious effects include irregular heartbeats (arrhythmias), QT prolongation (a heart rhythm problem), and blood disorders—quinine has been linked to life-threatening conditions like low platelet count, thrombotic thrombocytopenic purpura (a blood clotting disorder), and hemolytic uremic syndrome (which causes anemia, kidney failure, and low platelets).

Early warning signs of these blood disorders are bleeding from the gums, nose, or digestive tract, easy bruising, and small red spots on the skin. Quina is not safe in pregnancy—the safety data advises against it because quinine may harm the fetus.

It's also possibly unsafe during breastfeeding, since quinine can pass into breast milk.

Side effects, ingredient by ingredient Cinchona

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Cinchona.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; heart-rhythm medications.
  • For scale: 492 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, double-check with your pharmacist if you take quinidine, quinine, or any QT interval-prolonging heart medications (Major severity). Also verify CYP2D6 substrate drugs, blood thinners (anticoagulants or antiplatelets), antacids, phenobarbital, or carbamazepine (all Moderate severity).

The medication search tool on this page can help you find your exact drugs.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Major medication interactions have been identified, and safety information is well characterized.

Quina is a potent herbal extract with serious interaction potential and a narrow safety margin. You should not consider it if you take heart medications, blood thinners, anti-seizure drugs, or any CYP2D6-metabolized medications without talking to your pharmacist or doctor first.

Avoid it entirely if you're pregnant or breastfeeding. If you have no contraindications, discuss dosing and monitoring with your healthcare provider.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jan 24, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Quina, straight from the product label.

Brand Hawaii Pharm
Barcode (UPC) 840253643575
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Jan 24, 2024
DSLD ID 301782
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Quina by Hawaii Pharm, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
0.7 mL
Maximum serving Sizes:
1 mL
Servings per container
120
UPC/BARCODE
840253643575
IngredientAmount% DV
Quina Bark Extract, Dry983 mg--

Other ingredients: Alcohol, Water, Glycerin

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Brand IP Statement(s)

Hawaii Pharm Herbal Extract Highest quality since 2008

Suggested/Recommended/Usage/Directions

Suggested use: Shake well before using. For adults add about 20-30 drops (0.7-1 mL, one full squeeze of the dropper bulb) to some juice or water, up to 4 times a day.

Precautions

Warning: We recommend to seek expert medical advice before taking.

Do not use if you are allergic to any ingredients.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

Consult your physician before giving to children under 18, during pregnancy, if nursing or taking medications.

May affect the ability to drive and operate machinery. May have contraindications, can cause side effects and adverse reactions. Do not use if seal is broken or missing.

Keep out of the reach of children!

Storage

Store in a cool dry place.

Seals/Symbols

cGMP Made in compliance with cGMP 21 CFR 111 in an FDA registered and inspected facility.

Organic Alcohol Based USA Made in United States of America

FDA Disclaimer Statement

This product has not been evaluated by the FDA and is not intended to diagnose, treat, cure or prevent any disease.

General Statements

Scan this QR-code to get 15% discount on your next purchase. Limited time deal.

Formula

Cinchona officinalis

Organic Alcohol Based

Formulation

Only natural ingredients Purity is laboratory tested and verified

All the raw materials are gluten-free by their nature No artificial colors, flavors, or preservatives

Not tested on animals

Organic Alcohol Based

Made in USA, Hawaii

FDA Statement of Identity

Herbal Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Quina by Hawaii Pharm label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Quina label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Quina by Hawaii Pharm

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size0.7 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.

Quina Bark Extract, Dry

Interacts with
492 drugs
983 mg per serving Form: Cinchona officinalis Bark Extract, Dry

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...

Quina Bark Extract, Dry monograph & interactions

Other (inactive) ingredients: Alcohol, Water, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Quina by Hawaii Pharm Drug Interactions

Want to check YOUR meds against Quina?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
492Drugs
3 Major 473 Moderate 16 Minor

Ingredients driving the most interactions

Quina Bark Extract, Dry 492

Individual Drug Interactions

The ingredients in Quina interact with 492 drugs. Click any drug to see the details.

1 of the 1 ingredient in Quina interact with drugs. Each result below shows which ingredient is responsible. Quina Bark Extract, Dry

Each ingredient & the kinds of drugs it affects

For each ingredient in Quina with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Quina Bark Extract, Dry11 drug types · 492 drugs

Quinidine

Theoretically, taking cinchona might increase plasma levels and adverse effects of quinidine.
Cinchona contains quinidine.

Likelihood Probable Evidence D
Quinine

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

Likelihood Probable Evidence D
Antacids

Theoretically, taking cinchona might decrease the effectiveness of antacids. Theoretically, taking antacids might also increase the risk of adverse effects from cinchona.
Some research shows that taking cinchona lowers stomach acid pH. In addition, some research shows that taking antacids might increase urinary pH. Theoretically, this may increase the amount of quinidine, a constituent of cinchona, reabsorbed in the renal tubules and increase the risk of quinidine toxicity.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, taking cinchona might increase the drug effects and risk of bleeding with anticoagulant and antiplatelet drugs.
In vitro evidence shows that the alkaloids quinine, quinidine, and cinchonine, constituents of cinchona, inhibit platelet aggregation.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, taking cinchona might increase the adverse effects of carbamazepine.
Clinical research shows that taking quinine, a constituent of cinchona, increases the peak plasma concentration and area under the curve of carbamazepine.

Likelihood Probable Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, taking cinchona might inhibit cytochrome P450 2D6 (CYP2D6) and increase levels of drugs metabolized by this enzyme.
Quinidine, a constituent of cinchona, inhibits CYP2D6-mediated metabolism in humans.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Theoretically, taking cinchona might increase serum levels of digoxin.
Quinine and quinidine, which are constituents of cinchona, decrease clearance of digoxin and increase serum digoxin levels in humans.

Likelihood Possible Evidence D
Phenobarbital (Luminal)

Theoretically, taking cinchona might increase the adverse effects of phenobarbital.
Clinical research shows that taking quinine, a constituent of cinchona, increases the peak plasma concentration and area under the curve of phenobarbital.

Likelihood Probable Evidence D
Qt Interval-Prolonging Drugs

Theoretically, taking cinchona with other QT interval-prolonging drugs might cause an additive effect and increase the risk of ventricular arrhythmias.
Quinidine and quinine, which are constituents of cinchona, prolong the QT interval.

Likelihood Possible Evidence D
H2-Blockers

Theoretically, taking cinchona might decrease the effectiveness of H2-blockers.
Some research shows that taking cinchona lowers stomach acid pH.

Likelihood Possible Evidence D
Proton Pump Inhibitors (Ppis)

Theoretically, taking cinchona might decrease the effectiveness of PPIs.
Some research shows that taking cinchona lowers stomach acid pH.

Likelihood Possible Evidence D
Quina Bark Extract, Dry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Quina, from the product label.

Hawaii Pharm

See all Hawaii Pharm products
Name
Hawaii Pharm LLC
Street Address
510 Sumner St. Ste. 613
City
Honolulu
State
HI
ZipCode
96817
Phone Number
888-854-2924
Web Address
www.hawaiipharm.com
Pharmacist Counseling Corner

Quina by Hawaii Pharm: Common Questions

Does Quina by Hawaii Pharm interact with any medications?
Yes. Based on its ingredients, Quina has a known interaction with 492 medications, including 3 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Quina contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Can I take Quina if I'm pregnant or breastfeeding?
No. Quina is likely unsafe in pregnancy because quinine in the bark may harm the fetus. It's also possibly unsafe while breastfeeding, since quinine passes into breast milk. Talk to your doctor about alternatives if you need treatment during either time.
What are the most common side effects?
From oral use, diarrhea, nausea, ringing in the ears, and vomiting are the most common. Rare but serious side effects include irregular heartbeats and blood disorders—watch for bleeding from the gums or nose, easy bruising, or small red spots on skin.
Does Quina actually work for muscle cramps or the other uses listed?
We don't have strong evidence yet. The product is marketed for muscle cramps, malaria, cancer, respiratory infections, hemorrhoids, and influenza, but the research isn't robust enough to say whether it works for any of these.
Why is this product so risky with other medications?
Quina contains quinine and quinidine, which are powerful alkaloids. They slow how your liver clears many drugs, can affect your heart rhythm, and thin your blood. That's why it interacts with so many medications.
What's cinchonism?
Cinchonism is a syndrome of side effects from prolonged use or high doses of cinchona (quina bark). It's one of the rare but serious adverse effects listed for this product.

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

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Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Quina label
Go deeper

The Full Monographs Behind Quina’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Cinchona

Interacts with 492 drugs

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...

Read the full Cinchona monograph →
Sources

Sources & How We Checked

Quina's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 15 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Cinchona 15 references
  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Wichtl MW. Herbal Drugs and Phytopharmaceuticals. Ed. N.M. Bisset. Stuttgart: Medpharm GmbH Scientific Publishers, 1994.
  3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  4. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  5. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  6. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  7. Holt GA. Food & Possible Interactions with Drugs: Revised and Expanded Ed. Chicago, IL: Precept Press, 1998.
  8. Hardman JG, Limbird LL, Molinoff PB, eds. Goodman and Gillman's The Pharmacological Basis of Therapeutics, 9th ed. New York, NY: McGraw-Hill, 1996.
  9. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  10. Amabeoku GJ, Chikuni O, Akino C, Mutetwa S. Pharmacokinetic interaction of single doses of quinine and carbamazepine, phenobarbitone and phenytoin in healthy volunteers. East Afr Med J 1993;70:90-3.
  11. Shah BH, Nawaz Z, Virani SS, Ali IQ, Saeed SA, Gilani AH.The inhibitory effect of cinchonine on human platelet aggregation due to blockade of calcium influx. Biochem Pharmacol 1998;56:955-60. PubMed
  12. US Food and Drug Administration notice: Drug products containing quinine - enforcement action dates. Docket # 2006N-0476. Federal Register 2006 (December 15);71 (241): 75557-60.
  13. FDA Drug Safety Communication: New risk management plan and patient medication guide for Qualaquin (quinine sulfate). 07-08-2010. https://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm218202 (accessed 02/18/17).
  14. Dooms-Goossens A, Deveylder H, Duron C, et al. Airborne contact urticaria due to cinchona. Contact Dermatitis 1986;15(4):258. PubMed
  15. Bramer SL, Suri A. Inhibition of CYP2D6 by quinidine and its effects on the metabolism of cilostazol. Clin Pharmacokinet. 1999;37 Suppl 2:41-51. PubMed

See these in context on the Cinchona monograph →

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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