Lapachol

PhytochemicalNaphthoquinone

What is it

Lapachol is a naphthoquinone compound isolated from the inner bark of the lapacho (Tabebuia/Handroanthus) tree. It is the main bioactive constituent associated with the traditional South American 'pau d'arco' tea.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Anticancer (preclinical, historical trials)

Mixed Evidence

Historical trials were stopped due to toxicity; no current clinical use.

Antiparasitic (preclinical)

Mixed Evidence

In vitro activity; no clinical use.

How it works

Lapachol generates reactive oxygen species in cells and can interfere with mitochondrial function and DNA synthesis. In preclinical studies it has shown anticancer, antiparasitic (especially against Trypanosoma and Plasmodium species), and antimicrobial activity. Phase I clinical trials in the 1970s explored lapachol as a cancer treatment but were halted due to dose-limiting anticoagulant toxicity and gastrointestinal side effects. It is not approved as a therapeutic.

Dosage

No safe established supplement dose. Historical clinical trial doses caused toxicity. Some pau d'arco supplements contain small unstandardized amounts.

When and how to take it

Not recommended for routine use.

1 commercial form

Compare the main delivery options and what they’re best suited for.

Pau d'arco (Tabebuia) bark (contains lapachol)

Traditional source.

Variable lapachol content.

Safety

Anticoagulant effect at therapeutic doses (vitamin K antagonism), nausea, vomiting, anemia. Long-term safety is not established.

Who should be cautious

Avoid in pregnancy, breastfeeding, bleeding disorders, prior to surgery, and on anticoagulants.

Interactions

Significant interactions with warfarin and other anticoagulants. May potentiate bleeding when combined with antiplatelet drugs.

Frequently asked questions

Is lapachol a cancer treatment?⌄

No. Historical trials showed unacceptable toxicity at active doses.

Is pau d'arco tea safe?⌄

Short-term moderate use of standard pau d'arco tea has limited reported issues; high-lapachol concentrates carry bleeding risk.

References

Lapachol on Wikidata — Wikidata link

Lapachol (ChEBI:6377) — ChEBI link

Lapachol (PubChem CID 3884) — PubChem link

Lapachol on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Lapachol (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.