How to Source High-Quality Pau d'Arco: The Inner Bark Guide

If you've ever compared Pau d'Arco products online, you've probably noticed a wide price gap between brands. Some bags are cheap; others, like pure inner bark, cost more. It's tempting to think "it's just tree bark" — but in herbal sourcing, that assumption is the difference between a product that actually contains the compounds this site covers and one that mostly doesn't.

Why Quality Matters: The Naphthoquinone Factor

The reason Pau d'Arco (Handroanthus impetiginosus) is discussed at all is a specific group of compounds called naphthoquinones — chiefly lapachol and beta-lapachone.

These compounds aren't distributed evenly through the tree — they're concentrated in one thin layer. If a supplement doesn't come from that layer, the compounds this whole site discusses are largely absent from it.

The Inner Bark Secret: Phloem vs. Rhytidome

The most common quality issue in the Pau d'Arco market isn't the wrong tree — it's the wrong part of the tree. A Pau d'Arco log has three main parts:

• Rhytidome (outer bark) — the dead, corky exterior. Essentially no medicinal value.
• Phloem (inner bark) — the living tissue that transports nutrients. This is where the lapachol concentrates.
• Xylem (heartwood) — the dense wood used for construction and bows. Contains some quinoids, but far less than the inner bark.

Many manufacturers grind the whole log — bark, wood, and all — into powder, which dilutes the active compounds. True inner bark has a distinct pinkish-purple hue and a slightly sweet, earthy aroma; bark that looks like dark brown mulch or grey sand is likely mostly outer bark or heartwood.

What to Look for on a Label

The Latin name. Look for Handroanthus impetiginosus or its older synonym Tabebuia impetiginosa. There are over 100 Tabebuia species; if a label just says "Pau d'Arco" with no botanical name, that's a reason for caution.

"Inner bark only." A reputable seller states their product is "100% Inner Bark" or "Phloem." Labels that just say "Bark," "Whole Bark," or "Pau d'Arco Powder" often include the inactive outer layers.

Wildcrafted sourcing. Bark from trees growing in their native Amazon environment tends to have a more robust phytochemical profile than plantation-grown trees, since a tree's defensive chemicals are produced partly in response to its environment.

Where you source your inner bark from matters as much as anything else in this guide — see Why the Inner Bark of Pau d'Arco Is Important for the fuller anatomy of the tree. Our own pouches at Taheebo Wellness Tea are pure inner bark, sourced and labeled accordingly.

Preparation: The Decoction Method

Once you have quality bark, preparation matters. The active quinoids in Pau d'Arco aren't very water-soluble, so steeping like a bag of green tea wastes good bark.

• Use about 1–2 tablespoons of inner bark per quart of water.
• Use a glass or stainless steel pot (avoid aluminum, which can react with the tannins).
• Bring the water to a boil, then add the bark.
• Simmer for at least 8–15 minutes (some traditional protocols go up to 20 minutes).
• Strain and drink.

See our full brewing guide for a step-by-step walkthrough.

Precautions and Considerations

• Blood thinning: Pau d'Arco contains compounds that may have a mild anticoagulant effect. Consult your doctor if you're on blood-thinning medication or scheduled for surgery.
• Pregnancy: Because of lapachol's studied anti-proliferative properties, most herbalists recommend avoiding Pau d'Arco during pregnancy.
• Dosage: More isn't better — excessive consumption can cause nausea or gastrointestinal upset.

For a full breakdown, see Pau d'Arco Side Effects and Safety.

Where This Leaves Us

Sourcing the right Pau d'Arco takes a little extra attention, but it's the difference between a product that actually contains the compounds discussed on this site and one that largely doesn't. Look for Handroanthus impetiginosus inner bark, verify the source, and prepare it as a decoction.

References

1. 1.Zhang, J., et al. (2020). "Tabebuia impetiginosa: A comprehensive review on traditional uses, phytochemistry, and immunopharmacological properties." Molecules.
2. 2.Gomes, C., et al. (2021). "Beta-lapachone: Natural occurrence, physicochemical properties, biological activities, toxicity and synthesis." Phytochemistry.
3. 3.Leslie Taylor (2025). "The Healing Power of Rainforest Herbs," 2nd Edition. Rain-Tree Nutrition.
4. 4.Son, D., et al. (2006). "Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation." Journal of Ethnopharmacology.