# Lapachol

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/lapachol
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-03-20
**Evidence Score:** 2 / 10
**Category:** Compound
**Also Known As:** 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone, pau d'arco, lapacho, taheebo, ipe roxo, tecoma, trumpet tree bark extract

## Overview

Lapachol is a naturally occurring naphthoquinone extracted primarily from the heartwood of Tabebuia (pau d'arco) trees. It exerts biological activity largely by generating [reactive oxygen species](/ingredients/condition/antioxidant) and inhibiting [mitochondrial](/ingredients/condition/energy) electron transport chain enzymes, disrupting cellular respiration in parasitic and tumor cells.

## Health Benefits

• Antitumor activity, based on preliminary studies. • Trypanocidal effects, suggested by in vitro research. • Molluscicidal properties, observed in laboratory settings. • Leishmanicidal activity, indicated by experimental studies. • Antifungal effects, supported by early research.

## Mechanism of Action

Lapachol inhibits [mitochondrial](/ingredients/condition/energy) NADH-ubiquinone oxidoreductase (Complex I) and succinate dehydrogenase (Complex II), blocking ATP synthesis in susceptible cells. It also undergoes redox cycling to generate superoxide radicals and hydrogen peroxide, inducing [oxidative stress](/ingredients/condition/antioxidant) that damages DNA and lipid membranes in tumor and parasite cells. Additionally, lapachol intercalates into DNA and inhibits topoisomerase II, interfering with replication in rapidly dividing cells.

## Clinical Summary

Most evidence for lapachol comes from in vitro and animal studies; robust human clinical trials are largely absent. A Phase I human trial conducted in the 1970s by the U.S. National Cancer Institute evaluated lapachol in cancer patients but was terminated early due to dose-limiting toxicities including anticoagulation and gastrointestinal effects before efficacy endpoints could be reliably assessed. In rodent models, lapachol demonstrated significant tumor growth inhibition against Walker 256 carcinosarcoma, though effective doses approached toxic thresholds. The current evidence base is preliminary, and lapachol cannot be recommended as a therapeutic agent without further controlled human trials.

## Nutritional Profile

Lapachol (C15H14O3) is a naturally occurring naphthoquinone compound, not a dietary nutrient, and therefore lacks conventional macronutrient or micronutrient profiles. Molecular weight: 242.27 g/mol. It is not a source of protein, carbohydrates, dietary fiber, or conventional vitamins/minerals. Bioactive composition: Primary compound is 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone at near-100% purity in isolated form. Naturally found in the heartwood of Tabebuia (Handroanthus) species (pau d'arco bark), where it constitutes approximately 2–7% of dry heartwood weight alongside related naphthoquinones including beta-lapachone and xyloidone. Lapachol exhibits high lipophilicity (logP approximately 3.0–3.5), contributing to poor aqueous solubility (approximately 0.03 mg/mL in water at physiological pH), which significantly limits oral bioavailability. It is better absorbed in alkaline intestinal environments and undergoes hepatic first-pass [metabolism](/ingredients/condition/weight-management). In pau d'arco preparations (teas, tinctures), lapachol concentration is typically low (often below 1 mg per serving) due to its poor water solubility, meaning most commercial herbal preparations contain subtherapeutic levels. No dietary reference intakes (DRIs) exist. Concentrated supplemental or pharmaceutical doses studied in research contexts range from 1.5 to 15 mg/kg body weight, with toxicity (anticoagulant effects, nausea) reported at higher clinical doses.

## Dosage & Preparation

The search results do not provide information on clinically studied dosage ranges or standardization protocols. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Lapachol carries a significant safety concern: it is a vitamin K antagonist and can produce dose-dependent anticoagulation, causing prolonged prothrombin times similar to warfarin. Doses above approximately 1.5–2 mg/kg/day in humans produced nausea, vomiting, and bleeding risk in the NCI trial, leading to study discontinuation. Lapachol should not be combined with anticoagulants such as warfarin, heparin, or antiplatelet drugs due to additive bleeding risk. It is contraindicated in pregnancy, as animal studies indicate embryotoxic and teratogenic potential, and it should be avoided by individuals with clotting disorders or those scheduled for surgery.

## Scientific Research

The research dossier does not contain specific human clinical trials or meta-analyses documenting lapachol's efficacy in human subjects. Further peer-reviewed studies are necessary to establish clinical evidence.

## Historical & Cultural Context

Lapachol is derived from the lapacho tree, traditionally used in Brazilian folk medicine. Known as 'pau d'arco,' it has been used in Central and South America for unspecified traditional applications.

## Synergistic Combinations

β-lapachone, α-lapachone, quercetin, resveratrol, curcumin

## Frequently Asked Questions

### What is lapachol and where does it come from?

Lapachol is a 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone found primarily in the heartwood of Tabebuia avellanedae and related pau d'arco tree species native to Central and South America. It was first isolated in 1882 by E. Paterno and has since been studied for its antiparasitic, antifungal, and antitumor properties in laboratory settings.

### Can lapachol treat cancer?

Lapachol has demonstrated antitumor activity in vitro and in animal models, notably inhibiting Walker 256 carcinosarcoma in rodents, but it has not been proven effective in human cancer treatment. The NCI's Phase I human trial was discontinued because toxic doses were required to approach therapeutic blood concentrations, making its clinical use unfeasible without structural modification or targeted delivery.

### Is lapachol safe to take as a supplement?

Lapachol carries meaningful safety risks and is not considered safe for unsupervised supplementation. Its vitamin K antagonism can cause dangerous anticoagulation at doses above roughly 1.5 mg/kg/day, and side effects including nausea, vomiting, and bleeding episodes were observed in human study participants in the 1970s NCI trial.

### Does lapachol kill parasites like Leishmania or Trypanosoma?

In vitro studies show lapachol inhibits Leishmania spp. and Trypanosoma cruzi by disrupting mitochondrial electron transport and generating reactive oxygen species that are particularly toxic to these organisms, which have limited antioxidant defenses. However, these findings come from cell culture experiments, and no controlled human trials have confirmed antiparasitic efficacy or established safe dosing protocols.

### How does lapachol differ from beta-lapachone?

Lapachol and beta-lapachone are closely related naphthoquinones derived from the same pau d'arco source, but beta-lapachone is a cyclic ketone derivative formed by the acid-catalyzed cyclization of lapachol. Beta-lapachone has received significantly more modern research attention because it selectively activates NQO1 (NAD(P)H:quinone oxidoreductase 1), an enzyme overexpressed in many cancer cells, making it more tumor-selective than lapachol and a candidate for targeted oncology drug development.

### What does current clinical research show about lapachol's effectiveness in humans?

Most evidence for lapachol comes from in vitro and animal studies rather than human clinical trials, which remain limited. While laboratory research demonstrates promising antitumor, antiparasitic, and antifungal properties, these findings have not yet translated into robust clinical data in human populations. More rigorous human trials are needed to establish safety and efficacy for therapeutic use. Current supplement formulations are based largely on traditional use and preliminary research rather than definitive clinical proof.

### Does lapachol interact with common medications or antiparasitic drugs?

Limited research exists on lapachol's specific drug interactions, though its bioactive naphthoquinone structure suggests potential for interactions with medications metabolized by liver enzymes. Since lapachol is studied for antiparasitic and antimicrobial effects, concurrent use with pharmaceutical antiparasitics or antifungals may require medical supervision to prevent overlapping mechanisms or toxicity. Individuals taking prescription medications should consult a healthcare provider before adding lapachol supplements. No major interaction databases currently provide comprehensive lapachol drug interaction data.

### Who should avoid taking lapachol supplements, and are there specific populations at higher risk?

Pregnant and nursing women should avoid lapachol due to insufficient safety data and its bioactive naphthoquinone chemistry, which may pose fetal or infant risks. Individuals with liver disease or those taking hepatically metabolized medications should exercise caution, as lapachol may stress liver function. People with bleeding disorders or those on anticoagulants should consult a physician, as naphthoquinones can affect clotting. Those with known allergies to pau d'arco or related plants should avoid lapachol supplements.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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