There have been no reports in the literature of contraindications when a whole-bark decoction or tincture is used. However, at least one isolated phytochemical in pau d’arco (lapachol) has demonstrated abortifacient properties in animal studies. As there are no studies confirming the safety of traditional bark decoctions used by pregnant women (nor is there indication in traditional medicine systems using this plant during pregnancy), the use of pau d’arco during pregnancy is not recommended.

 

Large single dosages of pau d’arco decoctions (more than one cup) may cause gastrointestinal upset and/or nausea. Do not use in high doses unless under the advice of a qualified health practitioner; reduce dosage if nausea occurs.  There are definitely cautions to be aware of regarding pau d’arco.  Unfortunately, most studies differ in ways that make them difficult to compare.  One study focused on one derivitave compound from the wood of the Tabebuia tree called lapachol.  This study found that lapachol did possess some anti-cancer qualities.  Another study looked at off-the-shelf pau d’arco and determined that it did not improve the healt of it users at all.  Yet another research project showed that Lapachol taken in large does can possibly be toxic.

 

High doses of lapachol can cause uncontrolled bleeding, nausea, and vomiting.  Use of the whole bark is much safer than isolated lapachol.  The whole bark has no known serious side effects.  Pregnant or Lactating women should avoid use of pau d’arco.