Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Quassia Ingredients & Drug Interactions

by Herbalist & Alchemist

Liquid Category: Botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Quassia is a dietary supplement by Herbalist & Alchemist 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 dried Quassia wood extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Quassia by Herbalist & Alchemist

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

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: dried quassia wood extract. Quassia comes from the heartwood of tropical trees and has been used traditionally in herbal medicine.

The extract is suspended in a liquid base made with distilled water and ethyl alcohol.

Does it work?

No specific claim
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
General wellness

This Quassia product is marketed for general wellness, not a specific health condition, so there's no single claim to grade — see Quassia's own graded uses on its monograph.

Why this rating?
  • The label markets general wellness (“promotes healthy digestion”), not a specific health condition, so there is no single claim to grade against clinical-evidence data.

The evidence we hold doesn't establish whether quassia works for seborrheic dermatitis, lice, rosacea, or other conditions — the data shows insufficient reliable evidence for any of these uses. That doesn't mean it's ineffective; it means the research we have access to isn't strong enough yet to say one way or the other.

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.

Taken by mouth in medicinal amounts, quassia can irritate your mouth and throat lining and cause nausea and vomiting. Long-term use raises a more serious concern: it's been linked to vision changes and even blindness.

The safety data advises against use during pregnancy and while breastfeeding because we don't have enough information to know it's safe in those situations. Applied to the skin, quassia appears generally well tolerated with no reported adverse effects.

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 taking Herbalist & Alchemist's Quassia, double-check with your doctor or pharmacist if you take antidiabetes drugs, diuretics, digoxin (Lanoxin), H2-blockers, antacids, or proton pump inhibitors (PPIs). Quassia may lower blood sugar, compound potassium loss, affect heart medication levels, and reduce the effectiveness of acid-reducing drugs.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula marketed for general wellness rather than one specific gradeable purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Quassia is best used under the guidance of someone who knows your full medication list — especially if you take diabetes drugs, diuretics, heart medications, or acid-reducing drugs. The risk of digestive upset and the theoretical link to vision problems with long-term use mean it's not a casual-use herb.

Talk with your doctor or pharmacist before starting, particularly if you're pregnant, breastfeeding, or managing a chronic condition.

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 Mar 23, 2018.

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 Quassia, straight from the product label.

Brand Herbalist & Alchemist
Barcode (UPC) 667056123543
Net contents 2 fl. Oz.; 60 mL
Market status On market
Date entered into DSLD Mar 23, 2018
DSLD ID 174566
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Kosher
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 Quassia by Herbalist & Alchemist, 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:
0.75 mL
Maximum serving Sizes:
1 mL
Servings per container
60
UPC/BARCODE
667056123543
IngredientAmount% DV
dried Quassia wood extract1 mL--

Other ingredients: distilled Water, Ethyl Alcohol

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.
Formula

Quassia amara

OK

General Statements

Promotes healthy digestion

Botanical preparation ratio 1:4

FDA Statement of Identity

Herbal Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: 15-20 drops (0.75-1 mL) in juice or water. Take 3 times per day. Shake well before using.

Precautions

Contraindications: Do not use during pregnancy or give to young children unless otherwise directed by a qualified expert.

Contraindications: Do not use during pregnancy or give to young children unless otherwise directed by a qualified expert. Keep out of children's reach

FDA Disclaimer Statement

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

General

NO. QSA-2 1732MO

Seals/Symbols

OK

See for yourself

Quassia by Herbalist & Alchemist label

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

What’s inside

The Ingredients in Quassia by Herbalist & Alchemist

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

Serving size0.75 mL Dosage formLiquid Servings per container60 Amounts shown are per serving.

Dried Quassia wood extract

Interacts with
198 drugs
1 mL 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....

Dried Quassia wood extract monograph & interactions

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

Interaction report

Quassia by Herbalist & Alchemist Drug Interactions

Want to check YOUR meds against 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

Each ingredient & the kinds of drugs it affects

For each ingredient in 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.

dried Quassia wood 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
The maker

Brand information

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

Herbalist & Alchemist

See all Herbalist & Alchemist products
Name
Herbalist & Alchemist, Inc.
City
Washington
State
NJ
ZipCode
07882
Phone Number
800-611-8235
Web Address
www.herbalist-alchemist.com
Pharmacist Counseling Corner

Quassia by Herbalist & Alchemist: Common Questions

Does Quassia by Herbalist & Alchemist interact with any medications?
Yes. Based on its ingredients, 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?
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 take quassia if I'm pregnant or breastfeeding?
No — the safety data advises against it. There's not enough information to know it's safe, and traditional use has raised concerns. Talk with your doctor or pharmacist before using quassia if you're pregnant, breastfeeding, or planning either.
What are the side effects of quassia?
Taken by mouth, it can cause mouth and throat irritation, nausea, and vomiting in medicinal doses. Long-term use has been linked to vision changes and even blindness, which is a serious concern. Applied to skin, it appears well tolerated with no reported side effects.
Does quassia actually work for skin conditions like seborrheic dermatitis or rosacea?
We don't have reliable evidence yet to say whether it works for these uses. The research available isn't strong enough to draw a conclusion either way.
What is quassia used for?
Quassia comes from tropical tree heartwood and has been used traditionally in herbal medicine, particularly for skin conditions and parasites like lice. However, the evidence supporting these uses isn't well established in our data.
Can I use quassia if I take a water pill or heart medication?
Not without checking first. Quassia may worsen potassium loss from diuretics and could affect how your heart medication works. Talk with your doctor or pharmacist before combining them.

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

Not sure if Quassia is safe with your meds?

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.

Quassia label
Sources

Sources & How We Checked

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

Keep exploring