Educational information, not medical advice — ask your doctor or midwife.
Nogal is the Andean walnut, Juglans neotropica, a tall tree of the high Andes. Its leaves, bark, green husks and nuts have all been used in folk practice. It grows in Peru, Ecuador, Colombia and Bolivia.
The nut is an ordinary food. The green husk is best known as a dye. It stains hair, skin, wool and wood a deep brown-black.
Folk healers also made washes, gargles and teas from the leaves and bark. These were used for skin trouble, mouth sores, loose stools and gut worms.
Here is the honest verdict. Human evidence for any of these uses is very thin. Most research looks at the tree's chemistry, not at treating people.
Long use in a tradition tells you a plant is familiar. It does not tell you the plant works, and it does not tell you it is safe. That point applies to everything on this page and is not repeated below.
No mechanism for nogal has been confirmed in people. What follows comes from the laboratory.
The green husk and bark are rich in juglone. In test tubes, juglone slows the growth of some bacteria, fungi and yeasts. Whether that happens on human skin or in the gut is not established.
The leaves and bark also hold a lot of tannins. Tannins bind to proteins and make tissue feel tight and dry. That is the likely reason a leaf wash feels drying on weepy skin.
Tannins can also firm up the gut lining in a general way. This is a plausible reason behind the old use for loose stools. It has not been tested properly in people with diarrhoea.
In cell studies juglone can damage cells, including healthy ones. Some writers turn this into an anti-cancer or anti-parasite claim. That jump is not supported by human trials, and the same property is why strong husk preparations can irritate.
The dye effect is simple chemistry, not medicine. Juglone reacts with keratin, the protein in hair and skin, and leaves a lasting brown stain.
You may meet nogal in these forms:
- Dried leaves, sold loose by Andean herb sellers for tea or a skin wash. - Bark pieces for a boiled decoction. - Fresh or dried green husks, used mainly as a dye.
Other forms on sale today:
- Tinctures and capsules of leaf or husk, sold online, often under walnut or black walnut names. - Hair-darkening rinses and cosmetic dyes. - The shelled nut and its oil, eaten as food.
Market labels are often vague. Products may mix Juglans neotropica with the common walnut or the North American black walnut. If a label just says walnut hull, you cannot tell which tree it came from.
Nogal has long traditional standing in the Andes. Quechua and mestizo healers used leaf and bark washes for itching, rashes, sores and fungal skin trouble. Gargles were used for sore gums and mouth ulcers.
Leaf or bark teas were taken for loose stools and for gut worms. Some communities used them after childbirth as a drying wash.
The husk dye is older and better documented than any medical use. It coloured wool, cloth, wood and hair across the Andean highlands, and still does.
The timber was prized for furniture, which is part of why wild trees became scarce. None of this history is a reason to treat yourself with it.
Stop using nogal and see a doctor if any of these happen:
- Your rash spreads, blisters, weeps or gets more painful. - Diarrhoea lasts more than two days, or has blood or fever with it. - You cannot keep fluids down, or you feel faint and dry. - You get belly pain, dark urine or yellow skin or eyes (signs of liver trouble). - Mouth sores do not heal within two weeks.
Call emergency services if you get swelling of the lips, face or throat, a widespread hives rash, or trouble breathing after any walnut product. That can be a severe allergic reaction.
In the United States, the United Kingdom and the European Union, nogal is sold as a supplement, a cosmetic dye or a food nut. It is not approved as a medicine anywhere, and no health claim is authorised for it.
The tree itself is listed as endangered, and timber trade from Ecuador, Peru and Colombia is restricted.
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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