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Usnea

Usnea barbata

Herbs & Roots. Western & European.

Also called Old man's beard, Beard lichen

Spanish: Barba de viejo

Liver risk if swallowed

A grey, hair-like lichen that hangs from trees and is used on the skin for minor infections.

Did you know? Usnea is not one organism but a partnership of a fungus and an alga or cyanobacterium that live together.

What it may help, and how strong the proof is

Infections. Lab tests show activity against some bacteria and fungi. Human trials are missing.
Traditional proof
Skin. Used on minor skin wounds and rashes in folk medicine. Little proof exists.
Traditional proof

Parts of the body

Immune system, Skin & hair

Traditional use

European and North American folk healers used the lichen for wounds, skin problems, and coughs. Today it is mostly used on the skin.

How it is classified

Herbal actions: Antimicrobial, Antifungal, Vulnerary. Energy: neutral.

How people take it

For skin use only, a weak tea or diluted tincture can be dabbed on minor problems. Swallowing it is not advised because of liver risk.

Tincture and topical.

Where to get it

Grows on tree bark and branches in cool, clean air across Europe, Asia, and the Americas. Sold as dried lichen and tinctures. Strength varies with how and where it was collected.

Be careful

Usnic acid, a compound in usnea, has caused serious liver injury, including liver failure in people who took it as a weight-loss product. Do not swallow usnea products. Skin use can cause rash or irritation.

Avoid if: liver disease; pregnancy.

Mixing with other things

Works well together
Both appear in folk cold and infection blends.
Works well together
Both are used in folk infection blends for minor skin problems.
Use caution
Alcohol (beer, wine, spirits)
Alcohol adds liver stress, which matters because usnic acid can injure the liver.

The honest take

Usnea has lab evidence for fighting germs, but almost no human studies. The real safety issue is usnic acid, which has caused serious liver injury when swallowed. Skin use is the lower-risk choice, and swallowing it is not worth the risk.