Common name: Old man’s beard
Botanical name: Usnea barbata
© Martin Wall
Parts used and where grown
Usnea, also known as old man’s beard, is not a plant but a lichen—a symbiotic
relationship between an algae and a fungus. The entire lichen is used medicinally. Usnea looks
like long, fuzzy strings hanging from trees in the forests of North America and Europe, where
it grows.
Usnea has been used in
connection with the following conditions (refer to the individual
health concern for complete information):
Historical or traditional use (may
or may not be supported by scientific studies)
Due to its bitter taste, usnea stimulates digestion and was historically used by herbalists
to treat indigestion. It was also reportedly
used over 3,000 years ago in ancient Egypt, Greece, and China to treat unspecified
infections.1
Active constituents
Usnic acid gives usnea its bitter taste and also acts as an antibiotic in test tube
studies.2 Test tube studies have suggested an anti-cancer activity for usnic acid. However, this action
has not been sufficient to warrant further investigation in humans.3 Usnea also
contains mucilage, which may be helpful in easing irritating coughs. Again, this has not been studied in
humans.
How much is usually taken?
Usnea, 100 mg three times per day, can be taken in capsules.4 Tincture,
3–4 ml three times per day, can also be used.
Are there any side effects or interactions?
There are no known side effects of usnea. It is considered safe for use in children. The
safety of usnea during pregnancy and
breast-feeding has not been established.
At the time of writing, there were no well-known drug interactions
with usnea.
References:1. Tilford GL. Edible and Medicinal Plants of the West.
Missoula, MT: Mountain Press Publishing Company, 1997, 148–9.
2. Weiss RF. Herbal Medicine. Beaconsfield, UK: Beaconsfield
Publishers Ltd., 1988, 49.
3. Evans WC. Trease and Evans’ Pharmacognosy, 13th ed.
London: Baillière Tindall, 1989, 643.
4. Gruenwald J, Brendler T, Jaenicke C, et al. (eds). PDR for Herbal
Medicines. Montvale, NJ: Medical Economics, 1998, 1199–200.