Pau d'Arco
South American bark containing lapachol and beta-lapachone. Active against microbes and cancer cells in the laboratory, but the human evidence is one small supportive-care study, and the active compounds were toxic at therapeutic doses in cancer trials.
Where to buy
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What the science says
- Antimicrobial and anti-inflammatory activity in the laboratory Limited evidence
Beta-lapachone shows anti-inflammatory activity in cell and animal models and synergy with conventional antibiotics against methicillin-resistant Staphylococcus aureus in vitro. There is no controlled human trial of pau d'arco for candida or any infection.
- Oral mucositis during radiotherapy Limited evidence
A phase II study of a lapacho-based oral preparation in head and neck cancer patients described it as feasible and safe for reducing radiotherapy-induced mucositis. It was uncontrolled and small, so it cannot show efficacy.
- Anticancer claims Limited evidence
Lapachol and lapachone analogues have been extensively patented and studied against tumour cells, but early clinical work with lapachol was halted because doses needed for an antitumour effect caused unacceptable toxicity, including anaemia and prolonged clotting times.
Dosage & safety
How to take it
Interactions
With medications
- warfarin and other anticoagulants
Lapachol antagonises vitamin K, adding to anticoagulation and bleeding risk. do not combine
- aspirin, clopidogrel and other antiplatelet drugs
Additive bleeding risk on top of lapachol's effect on clotting. do not combine without medical supervision
With other supplements
- fish oil, garlic, ginkgo and other bleeding-risk supplements
Additive effect on clotting. avoid stacking them
- vitamin K
Works in the opposite direction to lapachol, making both unpredictable. do not use them to offset each other
Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.
Frequently asked questions
Does pau d'arco work for candida?
There is no controlled human trial of pau d'arco for candida or any infection; its antimicrobial activity has only been shown in the laboratory, so the evidence is limited.
Can pau d'arco treat cancer?
No. Early clinical work with lapachol, a pau d'arco compound, was halted because doses needed for an antitumour effect caused unacceptable toxicity, including anaemia and prolonged clotting times.
Is pau d'arco safe with blood thinners?
No. Lapachol in pau d'arco antagonises vitamin K and increases bleeding risk, so do not combine it with warfarin or other anticoagulants, and stop at least two weeks before surgery or dental extraction.
How much pau d'arco should I take?
No dose of pau d'arco has been validated; traditional use is a decoction of 1-2 g of inner bark up to three times daily, and capsules give 500-1,000 mg. Lapachol content varies enormously between products, and it should be avoided in pregnancy.
Scientific references
- Oral Lapacho-Based Medication: An Easy, Safe, and Feasible Support to Prevent and/or Reduce Oral Mucositis During Radiotherapy for Head and Neck Cancer
- An evaluation on potential anti-inflammatory effects of β-lapachone
- Lapachol and lapachone analogs: a journey of two decades of patent research(1997-2016)
Related in Immunity
- Vitamin C Limited evidence
- Zinc Moderate evidence
- Elderberry Limited evidence
- L-Lysine Limited evidence
- Echinacea Limited evidence
- Andrographis Moderate evidence