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Dietary supplement

Quassia 450 mg 4:1 Extract Ingredients & Drug Interactions

by TerraVita Premium Collection

Quassia 450 mg 4:1 Extract label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Oct 7, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Quassia 450 mg 4:1 Extract 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

Quassia 450 mg 4:1 Extract is a dietary supplement by TerraVita Premium Collection 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 Quassia 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 Quassia 450 mg 4:1 Extract by TerraVita Premium Collection

Ask about any prescription or over-the-counter medication and we check it for interactions with Quassia 450 mg 4:1 Extract by TerraVita Premium Collection — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Quassia 450 mg 4:1 Extract by TerraVita Premium Collection

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 Sep 10, 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 supplement contains one active ingredient: quassia extract, concentrated at a 4:1 strength and delivering 450 mg per capsule. Quassia is a plant extract traditionally used for skin and scalp conditions.

The capsule itself is made from gelatin and water — the only other ingredients present.

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 how well quassia works. For the conditions it's been studied in — seborrheic dermatitis, lice, and rosacea — the data is rated insufficient to draw reliable conclusions.

If you're considering this supplement for one of these uses, talk it over with your doctor about what the current evidence does and doesn't support.

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.

Quassia is likely fine in small food amounts, but medicinal doses of this supplement can irritate your digestive tract and cause nausea and vomiting. Long-term use carries a concern for vision changes and even blindness, so this isn't a supplement to take indefinitely without professional oversight.

The safety data advises against using quassia during pregnancy or while breastfeeding because the risks aren't well understood and traditional use raises concerns.

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.

Check with your doctor or pharmacist before taking this if you use antidiabetes drugs, diuretics (especially potassium-depleting ones), digoxin, H2-blockers, antacids, or proton pump inhibitors. Quassia has documented interactions with all of these medication types.

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.

Quassia Extract is best approached cautiously if you take diabetes medication, diuretics, digoxin, or acid-reflux drugs — several meaningful interactions are documented. Digestive upset and the possibility of vision problems with longer use are also real considerations.

Before adding this to your routine, check with your doctor or pharmacist about whether it's appropriate for your specific medications and health situation.

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 Apr 21, 2023.

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 450 mg 4:1 Extract, straight from the product label.

Brand TerraVita Premium Collection
Barcode (UPC) 064435212254
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Apr 21, 2023
DSLD ID 289444
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 450 mg 4:1 Extract by TerraVita Premium Collection, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
100
UPC/BARCODE
064435212254
IngredientAmount% DV
Quassia Extract450 mg--

Other ingredients: Gelatin, Water

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.
FDA Statement of Identity

A Dietary Supplement

Brand IP Statement(s)

Copyright 2017 TerraVita - Distributed by ZooScape LLC, All Rights Reserved.

Suggested/Recommended/Usage/Directions

Directions Take 1 capsule, 3 times daily, with meals.

General Statements

TerraVita is an exclusive line of premium natural products that use the finest, purest and most potent ingredients in the world. TerraVita's hallmarks are the highest possible standards of purity, potency, stability and freshness. All products are prepared with the greatest quality control, from raw materials through the entire manufacturing process, right up to the moment your product is sealed for freshness and shipped to you.

Please recycle!

FDA Disclaimer Statement

Statements not evaluated by FDA. Product not intended to diagnose, treat, cure, or prevent any disease.

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

See for yourself

Quassia 450 mg 4:1 Extract by TerraVita Premium Collection label

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

Quassia 450 mg 4:1 Extract 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 Quassia 450 mg 4:1 Extract by TerraVita Premium Collection

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container100 Amounts shown are per serving.

Quassia Extract

Interacts with
198 drugs
450 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....

Quassia Extract monograph & interactions

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

Interaction report

Quassia 450 mg 4:1 Extract by TerraVita Premium Collection Drug Interactions

Want to check YOUR meds against Quassia 450 mg 4:1 Extract?

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

Quassia Extract 198

Individual Drug Interactions

The ingredients in Quassia 450 mg 4:1 Extract interact with 198 drugs. Click any drug to see the details.

1 of the 1 ingredient in Quassia 450 mg 4:1 Extract interact with drugs. Each result below shows which ingredient is responsible. Quassia Extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Quassia 450 mg 4:1 Extract 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.

Quassia 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
Quassia Extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Quassia 450 mg 4:1 Extract, from the product label.

TerraVita Premium Collection

See all TerraVita Premium Collection products
Name
TerraVita Fine Whole Herbs
City
Brampton
State
Ontario
Pharmacist Counseling Corner

Quassia 450 mg 4:1 Extract by TerraVita Premium Collection: Common Questions

Does Quassia 450 mg 4:1 Extract by TerraVita Premium Collection interact with any medications?
Yes. Based on its ingredients, Quassia 450 mg 4:1 Extract 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 450 mg 4:1 Extract 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 a lack of safety information and traditional concerns about use during pregnancy and lactation. Talk with your doctor or pharmacist about what's safe for you during this time.
What are the side effects of quassia?
At medicinal doses, quassia can irritate your mouth and throat, and cause nausea and vomiting. A bigger concern is that long-term use may lead to vision changes and even blindness, so this isn't something to take indefinitely without medical guidance.
Does quassia actually work for skin conditions?
We don't have reliable evidence to say whether it works for seborrheic dermatitis, rosacea, or lice — the data is insufficient. If you're using it for one of these conditions, ask your doctor whether the evidence supports it for your situation.
What is quassia used for?
Quassia extract has been traditionally used for skin and scalp conditions like seborrheic dermatitis, rosacea, and lice, though the scientific evidence for these uses isn't established.
Are there any fillers in this supplement?
No — the capsule contains only gelatin and water as inactive ingredients. There are no other fillers or binders.

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

Not sure if Quassia 450 mg 4:1 Extract 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.

Quassia 450 mg 4:1 Extract label
Go deeper

The Full Monographs Behind Quassia 450 mg 4:1 Extract’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

Quassia 450 mg 4:1 Extract'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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