Pau d'Arco Through the Ages: From Indigenous Medicine to Modern Wellness

Important disclaimer

This article is for educational purposes only and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Pau d'Arco is not intended to diagnose, treat, cure, or prevent any disease. We summarize published research and traditional use — this is not a recommendation to use Pau d'Arco for any specific condition. Always consult a qualified healthcare professional before starting a new supplement, especially alongside an existing medical condition or medication.

Deep in the Amazon rainforest and across tropical Latin America, a canopy tree botanists know as Handroanthus impetiginosus (formerly Tabebuia impetiginosa) has a history of use that predates written record. This article traces that history — from a bow-making wood to a 1960s research subject to today's wellness market — and is deliberately kept separate from any claim about what drinking the tea does today.

Evidence key:Traditional UseLab / In VitroAnimal StudyHuman Trial

The Origin of the Name: "Bow Stick"

"Pau d'Arco" is Portuguese for "bow stick." Long before it was brewed as tea, the wood was prized for its durability and flexibility. The Guarani and Tupi tribes recognized it as some of the heaviest, most rot-resistant wood in the tropics, making it a primary material for hunting bows.

The Guarani and Tupi: Seeking "Strength and Vigor"

The Guarani and Tupi call the tree tajy — "to have strength and vigor." While the outer wood went to bows, it was the inner bark (the living phloem) that carried the traditional medicinal reputation. These tribes are recorded as using it for conditions ranging from colds and coughs to infections, snakebites, and — per traditional accounts — what would now be described as cancer. That's a historical/traditional claim, not a scientific one; see Pau d'Arco and Cancer for what the actual laboratory and clinical research shows.

The Kallawaya Healers

The tradition likely predates the Inca Empire, but the Kallawaya — the Incas' elite traveling physicians — are often credited with refining its use as part of a broader ethnobotanical pharmacopeia, treating it as a general tonic for internal inflammation, skin conditions, and systemic infection as traditionally understood.

Regional Folk Uses

Pending medical review. This section was added on September 20, 2026 and has not yet been reviewed by our medical reviewer.

Traditional Use

Ethnobotanical compilations record how different regions have used the bark. The Rain-Tree Tropical Plant Database lists Costa Rica for colds, fever, headaches and snakebite (and, in its wording, cancer), and Mexico for anemia and fever, alongside a much longer combined list for South America that spans respiratory, digestive, skin and circulation complaints. These are folk uses collected from herbal traditions. The compilation does not weigh the evidence behind them, and none of it shows that the bark or the tea treats any of these conditions.

Source: Rain-Tree Tropical Plant Database (L. Taylor); traditional-use records

More Folk-Use Records

Pending medical review. This section was added on September 26, 2026 and has not yet been reviewed by our medical reviewer.

Traditional Use

A 2020 review of the plant's traditional uses records further examples: the Callawaya making a concentrated tea from the inner bark for skin inflammatory conditions, Caribbean folk healers using the bark and leaves for toothaches, backaches and sexually transmitted diseases, and Brazilian traditional use for pain, inflammation and snake venom. The review also cites survey data showing that Brazilian traditional healers who prescribed the plant did so mostly for tumours and cancer. Like the Rain-Tree list above, these are records of what people did, not evidence that it worked.

Source: Zhang et al., Molecules (2020)

Traditional Preparation: The Decoction

Indigenous preparation used the decoction method (simmering), not a quick steep — the active compounds aren't very water-soluble. Traditional accounts describe simmering inner bark or heartwood for 15–20 minutes, with half a cup to a full cup taken several times daily during acute use. See our modern brewing guide for the method we recommend today.

The Modern Scientific Bridge

Human Trial

Scientific interest in Pau d'Arco grew in the 1960s after reports from Brazilian hospitals of physicians observing responses in patients with leukemia and various cancers who were using the bark. This led the National Cancer Institute to study lapachol as an isolated compound; when tested in Phase I human trials, the doses needed for a therapeutic effect also caused side effects like nausea. This is a historically important episode, but it describes isolated lapachol under 1970s clinical conditions — not a finding that today's whole-bark tea treats cancer. See Pau d'Arco and Cancer for the fuller, better-sourced research picture, including where it stands today.

Source: Historical NCI-era clinical interest, 1960s–1970s

Interestingly, whole-plant extract — the form indigenous tribes have used for generations — appeared in later research to have a lower side-effect profile than the isolated compound, likely because the other 100+ compounds in the whole bark act differently than lapachol alone.

Precautions and Considerations

Pregnancy: avoid — lapachol has shown abortifacient properties in animal studies.
Blood thinning: consult a healthcare provider if on blood-thinning medication or scheduled for surgery.
Dosage: excessive consumption can cause GI upset or nausea; more isn't better.

Where This Leaves Us

From hunting bows to a 1960s NCI research subject to today's wellness shelf, Pau d'Arco's history is a good story — but the history itself isn't evidence of efficacy. For what current lab, animal, and human research actually shows, start with What Scientific Research Says About Pau d'Arco.