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Botanical illustration of Old Man's Beard
MedicinalSourced entry

Old Man's Beard

Usnea barbata

Usnea, a beard-like lichen used in Chinese medicine and around the world for infections, wounds and coughs. Its usnic acid kills some microbes in the lab.

Safety at a glance

  • PregnancyNothing recorded
  • BreastfeedingNothing recorded
  • MedicinesNothing recorded
  • Who should avoid itNothing recorded
  • AllergiesNothing recorded
  • Toxicity1 note →

Tap a box to read the safety notes below. “Nothing recorded” means our sources don't cover it, not that it's safe.

What is Old Man's Beard?

Plant family
Parmeliaceae, a large family of lichens
Parts used
The whole lichen
Where it grows
Forests worldwide, hanging from tree branches
Genus
Usnea
Species
barbata

Also called

Usnea, Beard Lichen

Traditional names

Song Luo

Traditionally used for

  • Infections
  • Wounds
  • Cough (traditional)

Traditionally described as

  • Contains usnic acid

Traditions that use it

Natural compounds

Usnic Acid

Safety

Toxicity testing

  • Usnic acid taken by mouth can damage the liver. Weight-loss supplements containing it were linked to many reports of liver damage, and in 2001 the US FDA warned about one of them, LipoKinetix, which was then withdrawn.[1]Study

What does the research say?

Traditional use

These are traditional uses, not proven treatments.

  • Usnea is a lichen, not a plant. In Chinese medicine, where it's called song luo, it was first recorded in 101 BC and used as a tea for infections, malaria, wounds, snakebite and cough, though it's rarely used today. Around the world it has been used for tuberculosis, pain, fever, wounds and athlete's foot, and in salves, deodorants and tinctures.[2]Study

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

  • Usnea has been used against microbes in many countries and was being developed as a modern medicine just before penicillin arrived.[2]Study

  • In a 2026 lab study, an Usnea oil extract acted as an antioxidant and was active against Staphylococcus aureus bacteria and Candida yeast.[3]Study

In short

Usnic acid taken by mouth can damage the liver; weight-loss supplements containing it were withdrawn.

Sources

  1. [1] Hepatotoxicity of usnic acid and underlying mechanisms · DOI: 10.1080/26896583.2024.2366737Peer-reviewed study
  2. [2] Review of usnic acid and Usnea barbata toxicity · DOI: 10.1080/10590500802533392Peer-reviewed study
  3. [3] Antioxidant, Photoprotective, and Antimicrobial Potential of Oil Extract of Usnea barbata L. F.H.Wigg from Călimani Mountains, Romania · DOI: 10.3390/molecules31081324Peer-reviewed study

This information is educational and traditional in nature, and is not a substitute for professional medical advice. Unfamiliar word? See what these words mean.