Educational information, not medical advice — ask your doctor or midwife.
Stool wood is the bark of Alstonia boonei, a tall West African forest tree. In Ghana it is called nyamedua, the "God tree". The bark is very bitter and is usually boiled into a drink.
Healers have used it mainly for fever, malaria and joint pain. Human trials are almost absent. Long use in tradition is not proof that it works, and it is not proof that it is safe.
Most of what we know comes from animal and test-tube work. That work looks promising for fever and swelling. It does not tell you what the bark does in a person.
One point matters more than the rest. Malaria can kill, and this bark is not a tested malaria treatment. Suspected malaria needs a test and proper drugs from a clinic.
No one has shown how this bark acts in the human body. The honest answer is that it is not known.
In rats and mice, water extracts of the bark lowered fever. They also reduced swelling in injured paws. The size of the effect varied a lot between studies.
In test tubes, extracts slowed the growth of the malaria parasite. The effect was weak next to standard malaria drugs. Whether anything like it happens in a person is not established.
In cell and animal work the alkaloids appear to damp inflammation and dull pain signals. Some animal studies also show a fall in blood pressure and blood sugar. These are lab findings, not proven effects in people.
Dried stem bark is the main form. You may meet it as:
- Bark chips or shavings, boiled into a bitter drink - Bark powder, loose or packed in capsules - Alcohol tinctures and liquid extracts - Root bark and leaves, used less often than stem bark - Pastes and washes applied to the skin - Mixed herbal products sold in Ghana and Nigeria, where it is one of several plants
Bark is also the base of some registered herbal medicines in West Africa.
Few products are standardised to a measured alkaloid level. That means strength is largely unknown. Bark sold loose in markets can also be mislabelled or mixed with other Alstonia species.
Alstonia boonei has long standing across West and Central Africa. In Ghana the tree is nyamedua, the God tree, and was treated as sacred. Its soft, pale wood was carved into stools, drums and coffins, which gives the English names.
Healers in Ghana, Nigeria and Cameroon boiled the bark for fever and for malaria. Others gave it for joint pain, rheumatism and snakebite.
It also had a place in care after childbirth. Some traditions used it to help the womb clear and to bring on breast milk.
The plant appears in regional herbal pharmacopoeias and in national herbal medicine lists. Those records show what was used and how. They do not record a test of whether it helped.
Stop and get medical help the same day if you have a fever with chills, shaking, severe headache or vomiting. These can be malaria, which needs a test and real drugs.
Go to a hospital now if you have:
- Yellow eyes or skin, dark urine, or pain under the right ribs - Confusion, a fit, or trouble waking - Fainting, or a heartbeat that feels wrong - Shaking, sweating and confusion, which can mean low blood sugar - Vomiting that will not stop, or blood in vomit or stool - A spreading rash, swollen lips or tongue, or trouble breathing
Tell the staff exactly what bark you took and how much.
In the United States, the United Kingdom and the European Union it is not approved as a medicine. Where sold, it is a herbal supplement, so no agency has checked that it works.
In Ghana and Nigeria it is a recognised herbal medicine plant. Finished products there are meant to be registered with the national regulator, but market bark often is not.
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.
One email with the summary. We'll also send a short weekly evidence update — unsubscribe any time.
