Source Naturals Pau D'Arco Liquid Extract is derived from the highest-quality inner bark of the purple lapacho trees found in Brazil and Northern Argentina. A traditional herb that has been used for centuries, Pau d'Arco has now become a popular supplement in modern times. Contains no wheat, yeast, egg, soy, dairy, gluten, corn, salt, sugar, starch, preservatives, or artificial color, flavor or fragrance.