Pau d'Arco / Lapacho
Handroanthus impetiginosus
Photo credit: Giles Laurent
Safety information
Safety information
Toxicity: Lapachol causes dose-dependent toxicity — notably anti-vitamin K activity (anticoagulant/bleeding risk), nausea/vomiting, anemia at therapeutic-to-high doses; this ended its cancer trials. Genus Handroanthus review flags reproductive/general toxicity signals.
Contraindications: Pregnancy and breastfeeding (potential teratogenic/abortive and anticoagulant risk); bleeding disorders; before surgery; concurrent anticoagulant therapy. Avoid chronic high-dose use.
Interactions: Anticoagulants/antiplatelets (warfarin, aspirin) — additive bleeding risk via lapachol's anti-vitamin K effect; other anticoagulant herbs (guaco, ginkgo, garlic).
Pregnancy & breastfeeding: Contraindicated in pregnancy and breastfeeding (teratogenic/abortive and anticoagulant risk).
Evidence level
Supported by laboratory or animal studies; not yet confirmed in humans.
Preparations
tinctures, capsules; topical washes · inner bark
Part used: inner bark
decoction/tea of inner bark · inner bark/heartwood
Part used: inner bark/heartwood
Traditional use: anti-inflammatory, analgesic; skin inflammatory conditions, infections, fevers; folk 'anticancer', antimicrobial, antifungal (candidiasis), antiophidic
Proposed mechanism: naphthoquinones lapachol and beta-lapachone — antimicrobial, anti-inflammatory, antitumor; lapachol anti-vitamin K activity
Dosage note (descriptive only): avoid chronic high-dose use
Associated conditions
Nutritional notes
Not a food source; provides naphthoquinones, anthraquinones, flavonoids, benzoic acid derivatives.
Healing traditions
Sources (3)
- Red Lapacho ethnopharmacological commodity, J Ethnopharmacol, 2009
- Tabebuia impetiginosa review, Molecules (MDPI), 2020
- Anticancer potential and toxicity of genus Handroanthus, Toxicon, 2022