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Dietary supplement

Jamaican Quassia Ingredients & Drug Interactions

by Herbal Terra

Jamaican Quassia label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Jamaican Quassia 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: Moderate

Jamaican Quassia is a dietary supplement by Herbal Terra with 1 active ingredient. Its ingredients are commonly taken for loss of appetite, digestive upset, head lice (topical).Based on those ingredients, 198 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Jamaican Quassia by Herbal Terra

Ask about any prescription or over-the-counter medication and we check it for interactions with Jamaican Quassia by Herbal Terra — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Jamaican Quassia by Herbal Terra

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.

This product contains one active ingredient: wildcrafted Jamaican Quassia, a liquid extract from the Picrasma excelsa plant. The inactive ingredient is menstruum, a traditional herbal solvent used to create the extract.

Does it work?

Couldn't assess
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 assessable

This is a single-ingredient Quassia product and its label doesn't state a use — see Quassia's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold doesn't establish that Jamaican Quassia works for any condition. The data rates its use for seborrheic dermatitis, lice, and rosacea as having insufficient reliable evidence — meaning the research isn't there yet to confirm whether it actually helps.

The evidence, ingredient by ingredient Quassia

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.

Orally, quassia can irritate your mouth and throat tissues, and in medicinal amounts may cause nausea and vomiting. Long-term use raises concern for vision changes and even blindness.

Short amounts used in food appear fine, but larger or ongoing doses risk digestive tract irritation. The safety data advises against use during pregnancy and while breastfeeding because of traditional concerns and lack of safety information.

Side effects, ingredient by ingredient Quassia

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Quassia.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications; heart-rhythm medications.
  • For scale: 198 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 you start, double-check if you take antidiabetes drugs, diuretics, or digoxin — all carry Moderate-severity interaction risk. Also flag any H2-blockers, antacids, or PPIs you're on, as quassia may reduce their effectiveness (Minor severity).

Run your exact medications through the search tool on this page.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product is meant for topical or very short-term internal use only — it's not for ongoing supplementation. If you take blood sugar medication, diuretics, digoxin, or acid-suppressing drugs, check with your pharmacist before using it.

And avoid it entirely if you're pregnant or nursing.

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 Sep 25, 2020.

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 Jamaican Quassia, straight from the product label.

Brand Herbal Terra
Barcode (UPC) 617503345509
Net contents 4 Fluid Ounce(s); 120 mL
Market status On market
Date entered into DSLD Sep 25, 2020
DSLD ID 233706
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar 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 Jamaican Quassia by Herbal Terra, 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:
1 mL
Maximum serving Sizes:
1 mL
Servings per container
120
UPC/BARCODE
617503345509
IngredientAmount% DV
wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract970 mg--

Other ingredients: Menstruum

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.
Formulation

Origin of plant material: Jamaica.

Manufactured in the USA in an FDA registered facility

Sugar free

Dried herb/menstruum ratio: 1:3 Expertly extracted Laboratory tested 330 mg/1 mL Premium product Super concentrated liquid herbal extract

Non GMO

No artificial ingredients, GMO, gluten, color additives, fillers, preservatives or binders. Natural Gluten Free

Suggested/Recommended/Usage/Directions

Direction Shake well before use. Adults take up to 30 drops (1 mL, one full squeeze of the dropper bulb) in 3-4 fl. oz of juice or water up to 4 times a day. We recommend to seek expert medical advice before taking this or any other herbal supplements.

FDA Disclaimer Statement

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

Precautions

Caution May have contraindications.

Do not use if you are allergic to any ingredients.

Consult a physician before using during pregnancy, if nursing, or if you are on any medications.

Keep out of the reach of children.

Storage

Store in a cool, dry, dark place.

Formula

Picrasma excelsa

FDA Statement of Identity

Herbal Supplement

Seals/Symbols

Made in USA Made in an FDA registered facility Natural Gluten Free

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

See for yourself

Jamaican Quassia by Herbal Terra label

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

Jamaican Quassia 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 Jamaican Quassia by Herbal Terra

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

Serving size1 mL Dosage formLiquid Servings per container120 Amounts shown are per serving.

Wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract

Interacts with
198 drugs
970 mg per serving

Quassia is a tropical wood known for its very bitter taste, traditionally used as a digestive bitter and as a folk remedy for parasites and head lice....

Wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract monograph & interactions

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

Interaction report

Jamaican Quassia by Herbal Terra Drug Interactions

Want to check YOUR meds against Jamaican Quassia?

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
198Drugs
162 Moderate 36 Minor

Ingredients driving the most interactions

wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract 198

Individual Drug Interactions

The ingredients in Jamaican Quassia interact with 198 drugs. Click any drug to see the details.

1 of the 1 ingredient in Jamaican Quassia interact with drugs. Each result below shows which ingredient is responsible. wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Jamaican Quassia 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.

wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract6 drug types · 198 drugs

Antidiabetes Drugs

In animals, quassia extract reduced levels of fasting glucose. Theoretically, quassia might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels closely.
Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Theoretically, concomitant use with cardiac medications might increase the risk of therapeutic and adverse effects.

Likelihood Possible Evidence D
Diuretic Drugs

Overuse of quassia might compound diuretic-induced potassium loss. There is some concern that people taking quassia along with potassium depleting diuretics might have an increased risk for hypokalemia. Initiation of potassium supplementation or an increase in potassium supplement dose may be necessary for some patients.
Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), and hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.

Likelihood Possible Evidence D
Antacids

Theoretically, due to reports that quassia increases stomach acid, quassia might decrease the effectiveness of antacids.

Likelihood Possible Evidence D
H2-Blockers

Theoretically, due to reports that quassia increases stomach acid, quassia might decrease the effectiveness of H2-blockers. The H2 blockers include cimetidine (Tagamet), ranitidine (Zantac), nizatidine (Axid), and famotidine (Pepcid).

Likelihood Possible Evidence D
Proton Pump Inhibitors (Ppis)

Theoretically, due to reports that quassia increases stomach acid, quassia might decrease the effectiveness of PPIs. PPIs include omeprazole (Prilosec), lansoprazole (Prevacid), rabeprazole (Aciphex), pantoprazole (Protonix), and esomeprazole (Nexium).

Likelihood Possible Evidence D
wildcrafted Jamaican Quassia (Picrasma excelsa) liquid extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Jamaican Quassia, from the product label.

Herbal Terra

See all Herbal Terra products
Name
Herbal Terra
Pharmacist Counseling Corner

Jamaican Quassia by Herbal Terra: Common Questions

Does Jamaican Quassia by Herbal Terra interact with any medications?
Yes. Based on its ingredients, Jamaican Quassia has a known interaction with 198 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Jamaican Quassia 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 use this if I take blood sugar medication?
Not without checking first. Quassia may lower blood sugar on its own, so adding it to diabetes drugs could drop your levels too far (low blood sugar). Talk to your pharmacist or doctor about monitoring and dosing before you use it.
What are the side effects of taking quassia by mouth?
In medicinal amounts, quassia can irritate the mouth and throat, cause nausea and vomiting, and with long-term use may lead to vision changes and even blindness. That's why it's not meant for ongoing use.
Is it safe while pregnant or breastfeeding?
No. The safety data advises against use during pregnancy because of traditional concerns and a lack of safety data. Avoid it while breastfeeding as well — there isn't enough safety information.
Does Jamaican Quassia actually work for skin conditions or lice?
The evidence we have isn't enough to say. The data rates it as having insufficient reliable evidence for seborrheic dermatitis, rosacea, and lice — meaning the research hasn't proven whether it helps.
Can I take this with antacids or heartburn medication?
Not together. Quassia increases stomach acid, so it may reduce how well H2-blockers, antacids, and PPIs work. Check with your pharmacist before combining them.

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

Not sure if Jamaican Quassia is safe with your meds?

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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.

Jamaican Quassia label
Go deeper

The Full Monographs Behind Jamaican Quassia’s Ingredients

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

Herb & supplement monograph

Quassia

Interacts with 198 drugs

Quassia is a tropical wood known for its very bitter taste, traditionally used as a digestive bitter and as a folk remedy for parasites and head lice. Human evidence for these uses is limite...

Read the full Quassia monograph →
Sources

Sources & How We Checked

Jamaican Quassia'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 8 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.

Quassia 8 references
  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Robbers JE, Speedie MK, Tyler VE. Pharmacognosy and Pharmacobiotechnology. Baltimore, MD: Williams & Wilkins, 1996.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Jensen O, Nielsen AO, Bjerregaard P. Pediculosis capitis treated with quassia tincture. Acta Derm Venereol 1978;58:557-9. DOI
  6. Diehl C, Ferrari A. Efficacy of topical 4% Quassia amara gel in facial seborrheic dermatitis:a randomized, double-blind, comparative study. J Drugs Dermatol. 2013;12(3):312-5.
  7. Ferrari A, Diehl C. Evaluation of the efficacy and tolerance of a topical gel with 4% quassia extract in the treatment of rosacea. J Clin Pharmacol. 2012;52(1):84-8. PubMed
  8. Husain GM, Singh PN, Singh RK, Kumar V. Antidiabetic activity of standardized extract of Quassia amara in nicotinamide-streptozotocin-induced diabetic rats. Phytother Res. 2011;25(12):1806-12.

See these in context on the Quassia 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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