Educational information, not medical advice — ask your doctor or midwife.
Ipê roxo is the inner bark of a large South American tree, Handroanthus impetiginosus. It is sold as pau d'arco or taheebo, mostly as tea, capsules and tinctures. People take it for yeast problems, colds, inflammation and as a general tonic.
The tree grows across Brazil and much of tropical Latin America. Its purple flowers are well known, and the bark has a long folk history there. Long use in a tradition is not proof that a remedy works, and it is not proof that it is safe.
The honest verdict on evidence is simple. Good human trials are almost absent. Laboratory work on its compounds is interesting, but no trial shows it treats any illness in people.
It is not a harmless tea in large amounts. The main compound, lapachol, thinned the blood and caused vomiting in an older cancer study. That is why this page treats it with caution rather than as an everyday drink.
No one has shown how ipê roxo acts in the human body, because the human studies have not been done.
The proposed mechanism rests on naphthoquinones, a group of plant pigments in the bark. In test tubes, lapachol and beta-lapachone slow some bacteria, fungi and parasites. Whether that happens inside a person who drinks the tea is not established.
Beta-lapachone has been studied in cell and animal work on tumour cells. Those findings are early and do not show a benefit in people. They must not be read as proof that the bark treats cancer.
There is also an absorption problem. Much commercial bark holds very little lapachol, and little of it seems to reach the blood from tea. So lab results may not carry over to what is in the cup.
Ipê roxo is sold in several forms:
- Shredded or powdered inner bark, simmered as a tea or decoction - Tea bags labelled pau d'arco or taheebo - Capsules and tablets of dried bark powder - Liquid extracts and tinctures in alcohol - Creams, soaps and washes for the skin
Bark quality varies widely. Outer bark and wood are cheaper and are sometimes sold in place of inner bark. Buying from a seller who names the species is sensible.
Ipê roxo has a long record in Latin American folk medicine. Healers in Brazil, Paraguay and Argentina used bark decoctions for fevers, skin sores, wounds and stomach trouble. The Guaraní and other groups are often credited with the earliest use.
It reached a wide audience in the 1960s and 1970s. Brazilian press reports linked the bark to cancer, and demand spread to North America and Europe. Those reports were never backed by sound trials.
The tree is also valued as timber and as a street tree. Heavy bark harvesting has raised conservation concerns in parts of its range.
Stop taking it and get urgent medical help if you notice any of these:
- Bleeding that will not stop, or heavy nosebleeds - Blood in your urine, or black or bloody stools - Coughing or vomiting blood - Large bruises with no clear cause - Yellow skin or eyes - Severe or lasting vomiting
Also see a doctor if a skin infection spreads, if a fever lasts more than three days, or if symptoms you are treating keep getting worse.
In the United States, pau d'arco is sold as a dietary supplement. It is not approved to treat any disease. In the UK and EU it is sold as a food supplement or herbal product, not as a licensed medicine. Supplements are not checked for strength or purity the way medicines are.
Evidence grades and traditional-use labels are explained in our methodology. Nothing here is medical advice.
What it is typically used for, usual dose, cautions, and the study behind it where real trial data exists.
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