Afzelia (kawo) bark

What is Afzelia (kawo) bark?

What is Afzelia (kawo) bark?

It is the bark of Afzelia africana, a large tree of the West African savannah. In Hausa it is called kawo. Healers strip the bark, dry it, and boil it in water to make a drink or a wash.

The tree is best known for its hard timber and for leaves fed to cattle. The seeds and leaves are also used in folk practice. This page covers the bark only.

Here is the honest verdict. There are no good trials in people for any health use of this bark. Almost all the research is in test tubes and in rats.

Long use in a tradition is not proof that something works. It is also not proof that it is safe. Treat anything you read about kawo bark as untested, not as settled.

How does Afzelia (kawo) bark work?

How is it thought to work?

No one has shown how kawo bark acts in the human body. The ideas below come from the laboratory bench and from rodents.

In test tubes, bark extracts slow the growth of some bacteria and fungi. Whether that happens inside a person who drinks a bark tea is not known.

In rats, bark and stem extracts have lowered blood sugar and reduced swelling. These were short studies with small groups. They do not tell you what a dose does in a human.

The bark is rich in tannins. Tannins bind proteins and have a drying, puckering effect in the gut. That is the usual explanation for the traditional use in diarrhoea, and it is reasonable chemistry rather than proven benefit.

Saponins in the bark are soapy compounds. In cell studies they can damage cell membranes, which is one reason strong bark brews may irritate the stomach. The same property is also why saponin-rich plants are sometimes used as fish poisons.

What forms does Afzelia (kawo) bark come in?

How is it sold and used?

Most kawo bark is sold as dried bark, loose or in bundles, at local markets. You may also see it ground into a coarse powder.

Common traditional forms include:

- A decoction, made by boiling the bark in water - A cold water soak - Powdered bark mixed into food or pap - A wash or poultice placed on the skin

A few online sellers list capsules, tinctures or bark powder. These are not standardised. The label will not tell you how much active material is inside, and most are not tested for lead, mould or other plant matter mixed in.

Where it comes from:

What did tradition claim?

Afzelia africana has a long record in West African healing, across Nigeria, Niger, Ghana, Burkina Faso, Senegal and beyond. Written records of this use mostly date from colonial-era plant surveys onward, but the practice is older.

Hausa-speaking healers used kawo bark decoctions for fever, body pain and stomach complaints. Other groups used bark washes on wounds, sores and swellings.

The bark also appeared in treatments for back pain, hernia, convulsions and snakebite. In several areas it was part of remedies given to men for strength or fertility.

The tree itself carried value beyond medicine. It gave timber, fodder, shade and seeds used in cooking. That everyday standing helped keep the bark in use.

These are records of what people did. They are not records of what worked, and they should not be read as guidance to treat yourself.

What does Afzelia (kawo) bark help with?

• Fever: Tradition: bark decoctions were given as a hot drink for fever in several West African groups. Evidence: none in people. No trial has tested kawo bark against fever. Fever can signal malaria, typhoid or sepsis, all of which need fast medical care.
• Diarrhoea and stomach upset: Tradition: the bitter, drying bark was boiled and drunk to settle loose stools. Evidence: the bark is high in tannins, which bind proteins and can firm up gut contents. That is plausible chemistry, not a tested result. No human study supports it. Strong brews can also cause nausea and vomiting, so the effect may cut both ways.
• Body pain, back pain and joint pain: Tradition: bark was drunk or rubbed on for backache, rheumatic pain and general aches. Evidence: rodent studies report less swelling and less pain response with bark extracts. Rats are not people, and the doses used do not translate to a cup of tea. No human trial exists.
• Wounds and skin sores (applied to skin): Tradition: bark washes and poultices were put on wounds, boils and ulcers. Evidence: in test tubes, extracts slow some bacteria and fungi. Nobody has shown this works on a real wound. Raw plant material on an open wound can also carry soil bacteria and tetanus risk.
• Diabetes (folk use): Tradition: bark preparations were used for the symptoms now linked to diabetes, such as heavy thirst and passing a lot of urine. Evidence: several rat studies show lower blood sugar after bark or stem extracts. There is no human trial. Do not swap or stop diabetes medicine for this.
• Convulsions (folk use): Tradition: the bark appeared in remedies for fits in children and adults. Evidence: none in people. A seizure disorder needs a doctor. Untreated seizures can cause injury and, rarely, death.
• Snakebite (folk use): Tradition: bark was one of many plants used after snakebite. Evidence: none that it helps. Snakebite is a medical emergency and needs antivenom. Using a plant remedy instead of getting to hospital costs time that matters.
• Male sexual complaints (folk use): Tradition: in parts of West Africa the bark was taken by men for strength, potency or fertility. Evidence: a few rodent studies report changes in sperm counts or hormones, in both directions depending on the study and the dose. Nothing in people. The animal work is too mixed to lean on.

What are the side effects of Afzelia (kawo) bark?

• Nausea and vomiting
• Stomach pain or cramping
• Constipation, from the tannins
• Loss of appetite
• Bitter taste and dry mouth
• Skin rash or itching after contact
• Possible drop in blood sugar, seen in animals
• Unknown strain on the liver or kidneys with heavy or long use

Good to know:

Nobody has counted side effects properly, so we cannot say how common they are.

What is reported is mostly stomach upset from strong brews. Saponins can irritate the gut lining, and high-dose rodent studies have shown changes in liver and kidney tissue.

The bigger risk is not the bark itself. It is using it in place of care for something serious, such as malaria, an infected wound or diabetes.

How much Afzelia (kawo) bark should you take?

• Recommended daily: There is no established dose, and this page does not give one. No health authority has set a safe amount. No trial has tested one. Market bark and online powders vary in strength from batch to batch, so even a copied recipe is not repeatable. Traditional amounts were judged by the healer, by eye, and for a named person. That is not something a reference page can turn into a number.
• Best time of day: Time of day has not been studied and is unlikely to matter. If you are already taking it, keep it well away from your other medicines. A gap of about two hours is the usual sensible spacing with tannin-rich plants, because tannins can bind drugs and minerals in the gut.
• With or without food: Taking it with food is the gentler option. Tannin-rich and saponin-rich brews often irritate an empty stomach. Food may blunt nausea. It may also cut absorption, but since no dose is established, that trade-off is not meaningful here.
• Time to effect: There is no reliable answer, because no effect has been proven in people. It may do nothing at all. Any change you notice could be the illness passing on its own. Do not wait on a herb while a fever, a wound infection or high blood sugar gets worse.
• How long to take it: No safe length of use has been worked out. Traditional use was short and aimed at a passing problem, such as a bout of loose stools. There is no evidence behind taking it for weeks or months, and the long-term effects on the liver and kidneys have not been studied in people.