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Dietary supplement

Pau D'Arco 500 mg Of Inner Bark Ingredients & Drug Interactions

by NOW

Pau D'Arco 500 mg Of Inner Bark label
See full label image
Capsule 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 Pau D'Arco 500 mg Of 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 500 mg Of Inner Bark is a dietary supplement by NOW 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.

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Check Your Meds Against Pau D'Arco 500 mg Of Inner Bark by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Pau D'Arco 500 mg Of Inner Bark by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Pau D'Arco 500 mg Of Inner Bark by NOW

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 supplement contains one active ingredient: Pau D'Arco inner bark at 500 mg per capsule. The capsule itself is made from hypromellose, and the formula includes stearic acid as an inactive ingredient.

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 for pau d'arco is incomplete. Effectiveness ratings in our data show insufficient reliable evidence to rate it for cancer, peptic ulcers, wound healing, or dysmenorrhea.

That doesn't mean it doesn't work — it means the research backing isn't established yet in the data we have on file.

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 generally well tolerated at standard doses, but safety data in humans is limited. The lapachol constituent becomes a concern at higher doses — above 1.5 grams daily, it may cause anemia, increased bleeding risk, severe nausea, vomiting, and diarrhea.

Occupational exposure to pau d'arco sawdust can trigger asthma and dermatitis, though that's less relevant to taking the supplement itself. Avoid this product during pregnancy — the safety data advises against it due to possible harm to your baby.

The same goes for breastfeeding: there isn't enough safety information, so it's best not to use it while nursing. If you're pregnant, planning to become pregnant, or breastfeeding, talk with your doctor or pharmacist before considering this supplement.

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 you take this product, double-check your blood thinners and antiplatelet drugs with your doctor or pharmacist — that's where the moderate interaction risk sits. Pau d'arco may increase bleeding when combined with medications like warfarin, aspirin, or clopidogrel, especially at higher doses.

The 1.5 gram daily threshold for lapachol-related bleeding risk is a key number to confirm with your 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.

Pau D'Arco may be worth considering if you're interested in traditional herbal support, but the evidence for specific conditions isn't established in the data we hold. The bigger issue is its interaction with blood thinners and antiplatelet medications — if you take any of those, you'll need to check with your doctor or pharmacist before starting.

Avoid it during pregnancy and breastfeeding. Talk with your own healthcare provider about whether it's right for you.

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, 2019.

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 500 mg Of Inner Bark, straight from the product label.

Brand NOW
Barcode (UPC) 733739047267
Net contents 250 Veg Capsule(s)
Market status On market
Date entered into DSLD Dec 22, 2019
DSLD ID 212323
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Women (not pregnant or lactating), Gluten 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 500 mg Of Inner Bark by NOW, 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 Veg Capsule(s)
Maximum serving Sizes:
2 Veg Capsule(s)
Servings per container
125
UPC/BARCODE
733739047267
IngredientAmount% DV
Total Carbohydrates1 Gram(s)1%
Pau D’Arco1 Gram(s)--

Other ingredients: Hypromellose, Stearic Acid

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.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 2 capsules 1 to 2 times daily as needed.

Formulation

Pau D’Arco is derived from the inner bark of Tabebuia trees, which are native to the Amazonian rainforest. Pau D’Arco has been used by traditional herbalists for centuries. This traditional use is supported by the more recent discovery of many active compounds including lapachol and beta-lapachone.

Herbal Support

Non GMO

Vegetarian/Vegan

Not manufactured with yeast, wheat, gluten, soy, corn, milk, egg, fish, shellfish or tree nut ingredients.

Precautions

Caution: For adults only

Not recommended for pregnant or nursing women. Consult physician if taking medication or have a medical condition.

Keep out of reach of children.

Not manufactured with yeast, wheat, gluten, soy, corn, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

General Statements

Natural color variation may occur in this product.

Traditionally Used for Centuries

Botanicals/Herbs Family owned since 1968.

Seals/Symbols

Non GMO Project Verified nongmoproject.org

Triangle K

GMP Quality Assured

FDA Statement of Identity

A Dietary Supplement

Formula

Triangle K

Storage

Store in a cool, dry place after opening.

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

See for yourself

Pau D'Arco 500 mg Of Inner Bark by NOW label

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

Pau D'Arco 500 mg Of 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 500 mg Of Inner Bark by NOW

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

Serving size2 Veg Capsule(s) Dosage formCapsule Servings per container125 Amounts shown are per serving.

Pau D’Arco

Interacts with
122 drugs
1 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: Hypromellose, Stearic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Pau D'Arco 500 mg Of Inner Bark by NOW Drug Interactions

Want to check YOUR meds against Pau D'Arco 500 mg Of 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 500 mg Of Inner Bark interact with 122 drugs. Click any drug to see the details.

1 of the 1 ingredient in Pau D'Arco 500 mg Of 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 500 mg Of 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 500 mg Of Inner Bark, from the product label.

NOW

See all NOW products
Name
NOW Foods
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

Pau D'Arco 500 mg Of Inner Bark by NOW: Common Questions

Does Pau D'Arco 500 mg Of Inner Bark by NOW interact with any medications?
Yes. Based on its ingredients, Pau D'Arco 500 mg Of 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 500 mg Of 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.
Will this help with cancer or ulcers?
Our data shows insufficient reliable evidence to rate pau d'arco for cancer, peptic ulcers, wound healing, or dysmenorrhea. That means the research backing isn't established yet — you'd want to talk with your doctor about what the current evidence says and whether it fits your situation.
Can I take this if I'm on a blood thinner?
Not without checking first with your doctor or pharmacist. Pau d'arco has a documented moderate interaction with blood thinners and antiplatelet drugs — it may increase your bleeding risk. Your provider can tell you if it's safe for your specific medication and dose.
Is it safe to take at high doses?
No. At doses above 1.5 grams daily of the lapachol constituent, pau d'arco may cause anemia, increased bleeding, severe nausea, vomiting, and diarrhea. This product is 500 mg per capsule, so staying within safe limits depends on your total daily intake — talk with your pharmacist about the right dose for you.
Can I use this while pregnant or breastfeeding?
Avoid it during pregnancy — the safety data advises against it due to possible harm to your developing baby. There also isn't enough safety information for breastfeeding, so it's best to skip it then too. Talk with your doctor or pharmacist if you're pregnant, planning pregnancy, or nursing and considering supplements.
What are the side effects I should watch for?
At standard doses, pau d'arco is generally well tolerated, but human safety data is limited. At higher doses (above 1.5 grams daily), you may experience nausea, vomiting, diarrhea, or increased bleeding risk. If you notice any unusual symptoms, contact your pharmacist or doctor.

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

Not sure if Pau D'Arco 500 mg Of 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 500 mg Of Inner Bark label
Go deeper

The Full Monographs Behind Pau D'Arco 500 mg Of 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 500 mg Of 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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