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Dietary supplement

Pau D'Arco Ingredients & Drug Interactions

by Source Naturals

Pau D'Arco label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Pau D'Arco 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

Pau D'Arco is a dietary supplement by Source Naturals with 1 active ingredient. Its ingredients are commonly taken for infections (bacterial, fungal, yeast), inflammation, immune support.Based on those ingredients, 122 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Pau d'Arco inner bark 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 Pau D'Arco by Source Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with Pau D'Arco by Source Naturals — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Pau D'Arco by Source Naturals

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 3, 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 liquid contains one active ingredient: pau d'arco inner bark extract. Pau d'arco is a tree bark used traditionally for a range of purposes, though the clinical evidence behind those uses is not yet established.

The product also contains grain alcohol and purified water as inactive ingredients.

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 Pau D'arco product and its label doesn't state a use — see Pau D'arco'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 does not establish that pau d'arco works for cancer, peptic ulcers, wound healing, or dysmenorrhea. The product is marketed for these uses, but the research base does not yet support a clear rating for any of them.

The evidence, ingredient by ingredient Pau D'arco

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.

Pau d'arco may cause side effects at higher doses, and human safety data is limited. The lapachol compound in pau d'arco, taken in doses above 1.5 grams daily, can cause anemia, increased bleeding risk, severe nausea, vomiting, and diarrhea.

The safety data advises against using pau d'arco during pregnancy due to possible harm to the developing baby. There isn't enough data to know whether it's safe while breastfeeding—talk with your doctor or pharmacist for personalized advice.

Side effects, ingredient by ingredient Pau D'arco

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 — Pau D'arco.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 122 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 pau d'arco, check with your doctor or pharmacist if you're on any blood thinners (anticoagulants) like warfarin, or antiplatelet drugs like aspirin or clopidogrel. The interactions documented here span 122 medications across those categories.

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.

Pau d'Arco may be worth considering if you're interested in traditional herbal remedies, but the evidence for its effectiveness isn't yet established in the data we hold. Most importantly, if you take any blood thinner or antiplatelet medication, this product isn't right for you without checking first with your doctor or pharmacist.

Pregnant people and those breastfeeding should avoid it.

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 Dec 22, 2017.

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 Pau D'Arco, straight from the product label.

Brand Source Naturals
Barcode (UPC) 021078002659
Net contents 8 fl. Oz.; 236.56 mL
Market status On market
Date entered into DSLD Dec 22, 2017
DSLD ID 81345
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other
Intended target group(s) Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy 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 Pau D'Arco by Source Naturals, 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:
0.5 tsp
Maximum serving Sizes:
1 tsp
Servings per container
47
UPC/BARCODE
021078002659
IngredientAmount% DV
Pau d'Arco inner bark extract5 mL--

Other ingredients: Grain Alcohol, purified 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

Dietary Supplement

General Statements

Liquid extract

Source Naturals Pau D’Arco extract is made from the highest quality inner bark of the purple lapacho trees found in Brazil and northern Argentina. Ever since ancient times, when it was a standard for the medicine men of the Inca Empire, pau d’arco (also known as ipe roxo and taheebo) has been one of the most widely used herbs in South America. Its popularity is attributed to the active constituent, lapachol, which has been the subject of numerous scientific studies. This extract is more than 3 times as potent as common tinctures.

Suggested/Recommended/Usage/Directions

Suggested Use: Mix 1/2 to 1 teaspoon of this natural extract into tea or juice to drink between meals.

Shake well before using.

Precautions

Note: If you are pregnant, may become pregnant, or breastfeeding, consult your health care professional before using this product.

Do not use if either tamper-evident seal is broken or missing.

Keep out of the reach of children.

Formulation

Suitable for Vegetarians and Hypoallergenic: Contains no yeast, dairy, egg, gluten, corn, soy or wheat.

Suitable for Vegetarians and Hypoallergenic: Contains no yeast, dairy, egg, gluten, corn, soy or wheat.

Suitable for Vegetarians and Hypoallergenic: Contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.

General

SN0265 REV J131

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

See for yourself

Pau D'Arco by Source Naturals label

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

Pau D'Arco 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 Pau D'Arco by Source Naturals

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

Serving size0.5 tsp Dosage formLiquid Servings per container47 Amounts shown are per serving.

Pau d'Arco inner bark extract

Interacts with
122 drugs
5 mL per serving

Pau d'arco is a South American tree bark traditionally used for infections and inflammation, and it contains compounds like lapachol that show activit...

Pau d'Arco inner bark extract monograph & interactions

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

Interaction report

Pau D'Arco by Source Naturals Drug Interactions

Want to check YOUR meds against Pau D'Arco?

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
122Drugs
122 Moderate

Ingredients driving the most interactions

Pau d'Arco inner bark extract 122

Individual Drug Interactions

The ingredients in Pau D'Arco interact with 122 drugs. Click any drug to see the details.

1 of the 1 ingredient in Pau D'Arco interact with drugs. Each result below shows which ingredient is responsible. Pau d'Arco inner bark extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Pau D'Arco 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.

Pau d'Arco inner bark extract1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, pau d'arco might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that pau d'arco reduces platelet aggregation and may interfere with vitamin K. One clinical study shows that taking the lapachol constituent of pau d'arco in doses above 1.5 grams daily increases the risk of bleeding. The effects of whole pau d'arco or pau d'arco extract in humans are unclear.

Likelihood Possible Evidence D
Pau d'Arco inner bark extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Pau D'Arco, from the product label.

Source Naturals

Name
Source Naturals, Inc.
Street Address
P. O. Box 2118
City
Santa Cruz
State
CA
ZipCode
95062
Web Address
www.sourcenaturals.com
Pharmacist Counseling Corner

Pau D'Arco by Source Naturals: Common Questions

Does Pau D'Arco by Source Naturals interact with any medications?
Yes. Based on its ingredients, Pau D'Arco has a known interaction with 122 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Pau D'Arco 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 pau d'arco if I'm pregnant?
No. The safety data advises against using pau d'arco during pregnancy due to possible harm to the developing baby and lack of safety data. Talk with your doctor or pharmacist about what's safe for you.
Is pau d'arco safe while breastfeeding?
There isn't enough data to know either way. Talk with your doctor or pharmacist for personalized advice before taking it while breastfeeding.
What does pau d'arco actually do?
Pau d'arco is used traditionally for cancer, peptic ulcers, wound healing, and dysmenorrhea, but the evidence we have doesn't yet establish that it works for any of these. You'd want to discuss its use with your doctor.
At what dose does pau d'arco become risky?
The lapachol compound in pau d'arco can cause anemia, bleeding risk, nausea, vomiting, and diarrhea in doses above 1.5 grams daily. The product label or your pharmacist can tell you what dose this liquid provides per serving.
Why does pau d'arco interact with blood thinners?
Pau d'arco appears to reduce how platelets clump together and may interfere with vitamin K, both of which can increase bleeding risk when you're already on a blood thinner or antiplatelet drug.

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.

Pau D'Arco label
Go deeper

The Full Monographs Behind Pau D'Arco’s Ingredients

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

Herb & supplement monograph

Pau D'arco

Interacts with 122 drugs

Pau d'arco is a South American tree bark traditionally used for infections and inflammation, and it contains compounds like lapachol that show activity in lab studies. However, strong human...

Read the full Pau D'arco monograph →
Sources

Sources & How We Checked

Pau D'Arco'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 6 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.

Pau D'arco 6 references
  1. Gómez Castellanos JR, Prieto JM, Heinrich M. Red Lapacho (Tabebuia impetiginosa)--a global ethnopharmacological commodity? J Ethnopharmacol 2009;121:1-13. PubMed
  2. Guerra, Mde O., Mazoni, A. S., Brandao, M. A., and Peters, V. M. Toxicology of Lapachol in rats: embryolethality. Braz.J Biol. 2001;61(1):171-174. PubMed
  3. Felicio, A. C., Chang, C. V., Brandao, M. A., Peters, V. M., and Guerra, Mde O. Fetal growth in rats treated with lapachol. Contraception 2002;66(4):289-293. PubMed
  4. Son, D. J., Lim, Y., Park, Y. H., Chang, S. K., Yun, Y. P., Hong, J. T., Takeoka, G. R., Lee, K. G., Lee, S. E., Kim, M. R., Kim, J. H., and Park, B. S. Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular s
  5. Block JB, Serpick AA, Miller W, Wiernik PH. Early clinical studies with lapachol (NSC-11905). Cancer Chemother Rep 2. 1974;4(4):27-8.
  6. Algranti E, Mendonça EM, Ali SA, Kokron CM, Raile V. Occupational asthma caused by Ipe (Tabebuia spp) dust. J Investig Allergol Clin Immunol 2005;15(1):81-3.

See these in context on the Pau D'arco 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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