Pau d’Arco is an herbal remedy derived from the inner bark of specific tree species native to the tropical rainforests of Central and South America. Also known as Taheebo or Lapacho, this substance has been used for centuries by indigenous peoples for its health benefits. It remains a popular ingredient in traditional medicine and is now widely available as a dietary supplement.
Definition and Origin of Pau D’Arco
Pau d’Arco is the common name for the inner bark of several tree species in the genus Tabebuia and Handroanthus, particularly Tabebuia impetiginosa. These trees, indigenous to the Amazon basin and tropical regions of South America, can grow up to 125 feet tall and produce distinctive pink or violet flowers.
The medicinal preparation is sourced exclusively from the inner layer of the bark, known as the phloem. This inner bark concentrates active phytochemicals, including a group of compounds called naphthoquinones. The two most-studied naphthoquinones are lapachol and its derivative, beta-lapachone, which are responsible for the bark’s biological effects.
Traditional and Modern Health Claims
The use of Pau d’Arco by native South American tribes, such as the Incas, spans over a thousand years. Traditionally, the bark was employed as a broad-spectrum remedy for conditions including wounds, fevers, dysentery, infections, and inflammation.
Modern claims center on the bark’s antimicrobial, anti-inflammatory, and immune-supporting properties. Laboratory research shows that naphthoquinones, particularly beta-lapachone, exhibit antifungal activity against Candida species. Animal and in vitro studies suggest that Pau d’Arco extracts can inhibit the production of inflammatory chemicals, such as cyclooxygenase-2 (COX-2) and nitric oxide.
The bark has also been promoted for its role in cancer treatment, a claim originating with early research in Brazil during the 1960s. While laboratory studies indicate that lapachol and beta-lapachone may induce programmed cell death (apoptosis) in cancer cell lines, human clinical evidence is severely limited. High doses of the isolated compounds needed for these effects are associated with significant toxicity, and no clinical trial has confirmed Pau d’Arco’s effectiveness for treating cancer.
Preparation and Consumption Methods
The traditional and most common method of consuming Pau d’Arco is as a decoction, often called Pau d’Arco tea. Preparing a decoction involves boiling the dried inner bark, not steeping it, to properly extract the active compounds. Since naphthoquinones are not highly water-soluble, a sustained boiling process is necessary to maximize their presence in the liquid.
A common recommendation is to simmer the bark for at least 10 to 20 minutes. This creates a dark, slightly bitter liquid traditionally consumed a few times per day. Pau d’Arco is also widely available in modern supplement forms, including capsules, tablets, and liquid tinctures.
These commercial preparations offer convenience, but potency can vary significantly between products. Dosage is highly variable, and there are currently no universally accepted guidelines for its appropriate use. Consumers should ensure the product specifies the use of the inner bark from the correct Tabebuia species for optimal quality.
Safety Considerations and Potential Side Effects
Pau d’Arco is generally considered safe when consumed in moderate amounts, but high doses can lead to notable side effects. The most commonly reported adverse reactions include gastrointestinal disturbances such as nausea, vomiting, and diarrhea. Some individuals may also experience dizziness or, in rare cases, a discoloration of the urine.
A significant safety concern involves the compound lapachol, which has been shown to slow blood clotting. This blood-thinning property means that Pau d’Arco should be avoided by individuals taking anticoagulant or antiplatelet medications, like warfarin, as the combination could substantially increase the risk of bleeding. It is also advised to discontinue use before any scheduled surgery.
Due to a lack of safety research in certain populations, Pau d’Arco is not recommended for use by children, or by pregnant or nursing individuals. Animal studies involving lapachol have raised concerns regarding potential reproductive toxicity and effects on fetal development. Individuals with pre-existing liver or kidney conditions should also exercise caution, as high-dose animal studies suggest a potential for organ damage. Always consult a healthcare provider before beginning any new supplement regimen.