Usnea spp (U. barbata, U. californica, U. longissima) aka Old Man's Beard

Matthew Capowski

Staff member
This article on Usnea has a caution:

"Recently, Usnea has been used in weight-loss preparations with ill effects. Ingesting high quantities of the herb resulted in liver damage, liver failure and cerebral edema.

As with most lichens, ingesting significant quantities comes with risk and is not recommended."

The source is however not cited.