Educational information, not medical advice — ask your doctor or midwife.
Aliso is the bark of Alnus acuminata, a tall tree of the Andes. It is also called Andean alder. In Latin American folk medicine the bark is boiled into a tea or a skin wash.
The tree grows from Mexico down to Argentina. It likes wet ground along streams and hillsides. Farmers also plant it for timber and shade.
Most traditional use is for loose stools, sore gums and minor skin sores. The bark, and sometimes the young leaves, are the parts used. It is sold mainly as dried bark in Andean markets.
Here is the honest verdict. There are almost no human trials of aliso. Long traditional use is not proof that a remedy works, and it is not proof that it is safe.
No one has shown how aliso works in people. The ideas below come from the lab, not from patients.
Alder bark is high in tannins. Tannins bind proteins and make tissue feel tight and dry. This drying, puckering effect is the usual reason bark washes were used on wounds and loose stools.
In test-tube studies, alder bark extracts slow the growth of some bacteria and fungi. Whether that happens on human skin is not established.
Oregonin is a compound found in alder bark. In cell and animal studies it lowers markers of swelling. It has not been tested that way in people.
Some animal work suggests alder extracts protect liver cells from chemical damage. That finding has not been repeated in humans. Treat it as a starting point for research, not a reason to use the bark.
Dried bark is by far the most common form. Andean markets sell it loose, in strips or chips.
Forms you may meet: - dried bark, boiled into a tea or a wash - cut or dried leaves, used less often - liquid extracts and tinctures from herbal shops - bark powder in capsules, rare outside South America
Skin uses are usually a cooled wash or a soaked cloth. Mouth uses are a cooled rinse that is spat out.
Quality is hard to judge by eye. Loose bark can be mixed with other alder species or with unrelated bark. Buy from a seller who names the plant in full.
Andean healers used aliso bark for generations across Colombia, Ecuador, Peru and Bolivia. They simmered the bark and used the dark liquid warm.
Recorded folk uses included: - rinses for sore gums and mouth ulcers - washes for wounds, rashes and skin sores - teas for loose stools and stomach upset - baths and poultices for aching joints - drinks taken during fevers and colds
The tree mattered for more than medicine. Its wood was used for tools and building. Its roots feed nitrogen into poor soil, so it was planted on worn farmland.
These are records of what people did in the past. They are not instructions for home use today.
Stop and see a doctor if any of these happen.
- Diarrhoea lasts more than two days, or there is blood in the stool. - You have signs of dehydration: dry mouth, little urine, dizziness or sunken eyes. - A wound turns red, hot, swollen or starts leaking pus. - Mouth sores last more than two weeks. - You get yellow skin or eyes, dark urine, or pain under your right ribs.
Get emergency help for swelling of the lips, face, tongue or throat, or any trouble breathing. That can be a severe allergic reaction.
Aliso is not an approved medicine in the United States, the United Kingdom or the European Union. In the US it may be sold as a dietary supplement, which means no health claim has been reviewed. In Andean countries it is sold openly as a market herb under general herbal trade rules.
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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