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Dietary supplement

Pau d'Arco Inner Bark Ingredients & Drug Interactions

by Nature's Way

Pau d'Arco Inner Bark label
See full label image
Capsule Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Pau d'Arco Inner Bark 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 Inner Bark is a dietary supplement by Nature's Way 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. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Pau d'Arco Inner Bark by Nature's Way

Ask about any prescription or over-the-counter medication and we check it for interactions with Pau d'Arco Inner Bark by Nature's Way — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Pau d'Arco Inner Bark by Nature's Way

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 product contains one active ingredient: pau d'arco, the inner bark of a South American tree traditionally used for several purposes. The capsule itself is plant-derived, with magnesium stearate added as a binder.

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 isn't established in our data for pau d'arco's use in cancer, peptic ulcers, wound healing, or dysmenorrhea — we hold insufficient reliable evidence to rate it for any of these.

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 is not well studied in humans, and safety data is limited. At higher doses — particularly when the lapachol compound exceeds 1.5 grams daily — it may trigger anemia, severe nausea, vomiting, diarrhea, and increased bleeding risk.

The safety data advises against use during pregnancy due to possible harm to a developing baby. There isn't enough information to know whether it's safe while breastfeeding, so talk with your doctor or pharmacist before using it.

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 this product, check with your doctor or pharmacist if you're on any blood thinners (anticoagulants) or antiplatelet drugs such as warfarin, aspirin, clopidogrel, or apixaban — pau d'arco carries a Moderate risk of increasing bleeding when combined with these.

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 Inner Bark may be worth considering if you're exploring traditional herbal remedies, but it's important to be cautious if you take any blood thinner or antiplatelet medication — the bleeding risk is real. Human safety data is sparse, and higher doses carry notable side effects.

Talk with your doctor or pharmacist before starting it, especially if you're on any medications or pregnant or breastfeeding.

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 Feb 26, 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 Pau d'Arco Inner Bark, straight from the product label.

Brand Nature's Way
Barcode (UPC) 033674154083
Net contents 180 Vegan Capsule(s)
Market status On market
Date entered into DSLD Feb 26, 2020
DSLD ID 213142
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, 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 Inner Bark by Nature's Way, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
90
UPC/BARCODE
033674154083
IngredientAmount% DV
Pau d'Arco1.09 Gram(s)--

Other ingredients: plant-derived Capsule, Magnesium Stearate

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

Traditional South American remedy

Non GMO

Gluten free. No sugar, salt, yeast, wheat, soy, corn, dairy products, or artificial colors, flavors, or preservatives.

Vegan

General Statements

At Nature’s Way, we believe in quality you can trust. So, we start by sourcing botanicals from the places they grow best. Then we use three distinct levels of scientific testing methods to ensure ingredients meet our uncompromising standards. Look for the TRU-ID logo to find products certified for authenticity by independent, third party testing.

Nature’s Way Since 1969

Bottles made from 97% post-consumer recycled plastic

Seals/Symbols

Certified Authentic Tru-ID Non GMO Project Verified nongmoproject.org

Quality Global Sourcing Bottled & Tested In the USA

Formula

Pau d'Arco Inner Bark 1,090 mg per serving

FDA Statement of Identity

Dietary supplement

Suggested/Recommended/Usage/Directions

Recommendation: Take 2 Capsules twice daily with meals. For intensive use: Take 4 capsules three times daily.

Precautions

If you are pregnant, nursing, or taking any medications, consult a healthcare professional before use.

Keep out of reach of children.

Safety sealed with printed inner seal. Do not use if seal is broken or missing.

Brand IP Statement(s)

2019 Nature’s Way Brands, LLC

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

See for yourself

Pau d'Arco Inner Bark by Nature's Way label

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

Pau d'Arco Inner Bark 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 Inner Bark by Nature's Way

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

Serving size2 Capsule(s) Dosage formCapsule Servings per container90 Amounts shown are per serving.

Pau d'Arco

Interacts with
122 drugs
1.09 Gram(s) 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 monograph & interactions

Other (inactive) ingredients: Plant-derived Capsule, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Pau d'Arco Inner Bark by Nature's Way Drug Interactions

Want to check YOUR meds against Pau d'Arco Inner Bark?

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 122

Individual Drug Interactions

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

1 of the 1 ingredient in Pau d'Arco Inner Bark interact with drugs. Each result below shows which ingredient is responsible. Pau d'Arco

Each ingredient & the kinds of drugs it affects

For each ingredient in Pau d'Arco Inner Bark 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'Arco1 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 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Pau d'Arco Inner Bark, from the product label.

Nature's Way

See all Nature's Way products
Name
Nature's Way Brands, LLC
City
Green Bay
State
WI
ZipCode
54311
Phone Number
1-800-962-8873
Web Address
naturesway.com
Pharmacist Counseling Corner

Pau d'Arco Inner Bark by Nature's Way: Common Questions

Does Pau d'Arco Inner Bark by Nature's Way interact with any medications?
Yes. Based on its ingredients, Pau d'Arco Inner Bark 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 Inner Bark 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 if I'm on warfarin or aspirin?
Not without checking first. Pau d'arco may increase your bleeding risk when combined with blood thinners or antiplatelet drugs. Talk with your doctor or pharmacist about your specific medications before starting — they can tell you whether it's safe to combine.
Is this safe during pregnancy?
No. The safety data advises against use during pregnancy because of possible harm to a developing baby and lack of safety information. Talk with your doctor before taking it if you're pregnant or planning to become pregnant.
Is this safe while breastfeeding?
There isn't enough information to know either way. Talk with your doctor or pharmacist for personalized advice before taking this supplement while breastfeeding.
Does this actually work for cancer or ulcers?
The evidence isn't established in our data. We hold insufficient reliable evidence to rate pau d'arco for cancer, peptic ulcers, wound healing, or dysmenorrhea — so we can't say whether it works for these purposes.
What side effects should I watch for?
At higher doses — especially when the lapachol compound goes above 1.5 grams daily — pau d'arco may cause anemia, severe nausea, vomiting, diarrhea, and increased bleeding. Human safety data is limited overall, so watch closely and report any unusual symptoms to your doctor.

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

Not sure if Pau d'Arco Inner Bark 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.

Pau d'Arco Inner Bark label
Go deeper

The Full Monographs Behind Pau d'Arco Inner Bark’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 Inner Bark'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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