Now Foods, Pau D' Arco, 500 mg, 250 Capsules500 mg of Inner Bark Herbal Support Traditionally Used for Centuries A Dietary Supplement Botanicals Herbs Family Owned Since 1968 GMP Quality Assured Pau D' Arco is derived from the inner bark of Tabebuia trees, which are native to the Amazonian rainforest. Pau D' Arco has been used by traditional herbalists for centuries. This traditional use is supported by the more recent discovery of many active compounds including lapachol and beta lapachone.