Educational information, not medical advice — ask your doctor or midwife.
Cumaseba is the bark of Swartzia polyphylla, a large tree of the Amazon rainforest. Healers in Peru, Brazil and Colombia steep the bark in water or cane spirit. The bark, the inner wood and sometimes the resin are all used.
In folk practice it is taken for joint and muscle pain, for skin and fungal complaints, and as a general tonic. Long use in a tradition is not proof that a remedy works. It is also not proof that it is safe.
The honest verdict on evidence is short. No good human trials of cumaseba have been published. Everything below that sounds promising comes from tradition or from lab work on related plants.
You will see it sold as bark chips, as powder in capsules, and as alcohol tinctures. Quality and strength vary a lot between sellers. Nothing about the plant is tightly regulated.
Nobody has shown how cumaseba acts in the human body. The ideas below are proposals, not findings.
Swartzia species carry isoflavonoids and saponins. In test tubes, extracts of some Swartzia plants slow the growth of fungi and bacteria. Whether that happens on human skin or inside the body is not known.
Some plant saponins break open cell walls in lab dishes. That is a lab effect, not a treatment effect.
The traditional claim of easing joint pain is often explained as an anti-inflammatory action. That explanation has not been tested in people with cumaseba. Many tinctures are made with strong spirit, so some of what a user feels may come from the alcohol.
Common forms you may meet:
Dried bark chips, boiled into a decoction (a strong tea made by simmering).
Bark powder, loose or in capsules.
Tinctures and macerations in cane spirit or rum. These can be strongly alcoholic.
Topical oils and salves blended with other Amazon plants.
Blended tonic bottles sold as Amazonian formulas, where cumaseba is one name among many. Labels often fail to say how much is in the bottle.
Cumaseba has a long standing in Amazonian herbal practice, mainly in the Peruvian lowlands. Bark was simmered or soaked in cane spirit by local healers.
It was given for rheumatic pain, for wounds and skin infections, and as a strengthening tonic after illness. Some healers used it in steam or bathing preparations.
The timber is also valued and heavy, which is why the tree is logged. Market vendors in Iquitos and other river towns still sell the bark today. This page reports that history and does not recommend copying it.
Stop taking it and see a doctor if you get:
Yellow skin or eyes, dark urine, or pain in the upper right belly.
A rash, swelling of the lips or face, or trouble breathing. Breathing trouble is an emergency; call for help at once.
Vomiting, bad diarrhoea or belly pain that lasts more than a day.
Also see a doctor if the problem you are treating does not improve, or gets worse, within two weeks.
In the United States, the United Kingdom and the European Union, cumaseba bark is sold as a dietary or food supplement, not as a licensed medicine. No health claims are approved for it. The tree is also a timber species, so sourcing rules vary by country.
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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