The chemical compounds and active ingredients of Pau d'arco have been well documented, with much research focused on the long reported use treating various types of cancers. The presence of quinoids in pau d'arco is reported have shown the most documented pharmacological activity and are believed to be central to the plants efficacy. Studies in the 1970's largely focused on the ability of one specific quinoid, lapachol, to produce therapeutic effects against cancer. Focus on this and other single phytochemicals is due to the pursuit of patents. Isolated phytochemicals have shown a variety of strong effects on various ailments with highly effective treatments against cancers in laboratory animal testing. These chemicals are present in whole plant teas and decoctions as well, but whole plants are not patentable.
In studies, pau d'arco has demonstrated action against a number of disease-causing microorganisms, which supports its widespread use in herbal medicine. Its constituents have shown strong activity against bacteria, fungi, and yeast like Candida, Staphylococcus, Streptococcus, Helicobacter, tuberculosis, pneumonia, and dysentery. In addition to its isolated chemicals, a hot water extract of pau d'arco demonstrated antibacterial actions against Staphylococcus aureus and Helicobacter pylori which is a cause of stomach ulcers. It has also shown activity against various viruses such as influenza, Herpes I and II, and polio. It's antiparasitic properties have been shown against malaria, schistosoma, and trypanosoma.