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Dietary supplement

Quassia 4:1 Extract Powder Ingredients & Drug Interactions

by TerraVita Premium Collection

Quassia 4:1 Extract Powder label
See full label image
Powder 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 Quassia 4:1 Extract Powder 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 4:1 Extract Powder 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, Powder. 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 4:1 Extract Powder by TerraVita Premium Collection

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

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HelloPharmacist Scorecard of Quassia 4:1 Extract Powder 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 product contains one active ingredient: quassia extract powder in a 4:1 concentrate form. Quassia is a plant extract traditionally used for skin and scalp conditions.

There are no inactive ingredients listed.

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 quassia works for seborrheic dermatitis, lice, or rosacea — the data rates these uses as having insufficient reliable evidence. If you're considering it for any of these reasons, talk with your doctor or pharmacist about what the research actually shows and what alternatives might work better.

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, quassia can irritate your mouth and throat lining, cause nausea and vomiting, especially in medicinal amounts. Long-term use has been linked to vision changes and even blindness.

Applied to skin, it appears well tolerated with no reported adverse effects. Quassia is rated as likely unsafe during pregnancy because of traditional concerns and a lack of safety data — avoid it if you're pregnant or planning to become pregnant.

There isn't enough safety information available while breastfeeding either, so avoid use then too.

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 this product, check with your doctor or pharmacist if you take antidiabetes drugs, diuretic medications, digoxin, H2-blockers, antacids, or proton pump inhibitors. Quassia can affect how all of these work — some risks are serious and some are minor, but all warrant a conversation with your own healthcare provider.

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 considered only if you've talked it over with your doctor and you don't take blood sugar medication, diuretics, digoxin, or acid-reducing drugs. The effectiveness for skin and scalp conditions isn't established in our data, and there are real safety concerns with long-term oral use.

If you take any medications, check them against the list on this page or talk with your pharmacist before you start.

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 Jun 22, 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 4:1 Extract Powder, straight from the product label.

Brand TerraVita Premium Collection
Barcode (UPC) 064435212261
Net contents 1 Ounce(s)
Market status On market
Date entered into DSLD Jun 22, 2023
DSLD ID 290859
Product type Botanical
Supplement form Powder
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 4:1 Extract Powder 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:
0.25 Teaspoon(s)
Maximum serving Sizes:
0.25 Teaspoon(s)
Servings per container
28
UPC/BARCODE
064435212261
IngredientAmount% DV
Quassia Extract, Powder1000 mg--

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 Stir 1/4 of a teaspoon into a glass of water and consume 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 4:1 Extract Powder by TerraVita Premium Collection label

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

Quassia 4:1 Extract Powder 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 4:1 Extract Powder by TerraVita Premium Collection

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

Serving size0.25 Teaspoon(s) Dosage formPowder Servings per container28 Amounts shown are per serving.

Quassia Extract, Powder

Interacts with
198 drugs
1000 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, Powder monograph & interactions
Interaction report

Quassia 4:1 Extract Powder by TerraVita Premium Collection Drug Interactions

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

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, Powder 198

Individual Drug Interactions

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

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Quassia 4:1 Extract Powder 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 Extract, Powder6 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, Powder full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Quassia 4:1 Extract Powder, 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 4:1 Extract Powder by TerraVita Premium Collection: Common Questions

Does Quassia 4:1 Extract Powder by TerraVita Premium Collection interact with any medications?
Yes. Based on its ingredients, Quassia 4:1 Extract Powder 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 4:1 Extract Powder 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 this while I'm pregnant or breastfeeding?
No — quassia is rated as likely unsafe during pregnancy because of traditional concerns and lack of safety data. There also isn't enough safety information for breastfeeding, so avoid it then too. Talk with your doctor or midwife if you're looking for alternatives.
What is quassia used for?
Quassia extract has been traditionally used for seborrheic dermatitis (a flaky scalp condition), lice, and rosacea. However, the evidence doesn't establish that it actually works for any of these — there's insufficient reliable data. Applied to skin, it does seem well tolerated.
What are the side effects of taking quassia by mouth?
In medicinal doses, quassia can cause irritation in your mouth and throat, nausea, and vomiting. With long-term use, there have been reports of vision changes and blindness. These are serious reasons to use it only under medical guidance and never long-term without talking to your doctor.
Can this product lower my blood sugar?
Yes — animal studies show quassia extract reduces fasting glucose levels. If you take diabetes medications, quassia might add to their blood-sugar-lowering effect and raise your risk of low blood sugar (hypoglycemia). This is why close blood glucose monitoring and a conversation with your doctor are essential before you start.
Will this reduce how well my acid-reducing medication works?
Possibly. Quassia may increase stomach acid, which could decrease the effectiveness of H2-blockers (like cimetidine or ranitidine), antacids, or PPIs (like omeprazole). These are minor interactions, but worth mentioning to your pharmacist if you're on one of these drugs.

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

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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 4:1 Extract Powder label
Go deeper

The Full Monographs Behind Quassia 4:1 Extract Powder’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 4:1 Extract Powder'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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