History & Traditional Use
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.
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.
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
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.
References
- 1.Zhang, J., et al. (2020). "Tabebuia impetiginosa: A comprehensive review on traditional uses, phytochemistry, and immunopharmacological properties." Molecules. PMC7571111
- 2.Mosquera-Morales, L., et al. (2025). "In vitro antiproliferative activity in plants of the genus Tabebuia: A systematic review." Molecules. PMC12156312
- 3.Rain-Tree Tropical Plant Database. (2025). "Pau d'Arco (Tabebuia impetiginosa)."
- 4.Gomes, C., et al. (2021). "Beta-lapachone: Natural occurrence, physicochemical properties, biological activities, toxicity and synthesis." Phytochemistry.
- 5.Son, D., et al. (2006). "Inhibitory effects of Tabebuia impetiginosa inner bark extract on platelet aggregation and vascular smooth muscle cell proliferation." Journal of Ethnopharmacology.