4 Benefits of Usnea: Dosage & Safety

Usnea, popularly known as old man’s beard, is a lichen that’s been used as a traditional medicine in Asia, Africa, and Europe. Usnea has been used for pain relief, fevers, …

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Written by: Siobhan Mendicino
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Medical Review by: Daniel Powers, MS
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Usnea, popularly known as old man’s beard, is a lichen that’s been used as a traditional medicine in Asia, Africa, and Europe.

Usnea has been used for pain relief, fevers, wound healing, and to reduce inflammation.  

This article will look at the health benefits of usnea, its safety, and how to take it.

health benefits of usnea

What is Usnea?

Usnea, a type of lichen, can be found growing on trees and rocks. This specific type of lichen is known for its pale green appearance and fungus-like networks. 

Usnea is unique in that every part of the plant is medicinal. 

The scientific name for this herb is Usnea barbata. Usnea is a popular herb in traditional South African medicine. Hippocrates famously mentioned its ability to help with urinary issues. 

Usnea has been used as a traditional medicine to encourage wound healing, prevent bleeding, support urinary conditions, and reduce inflammation.   

Modern accounts recommend using this herb to manage wounds, prevent infections, and slow bleeding.

Research suggests that the active constituents that usnea contains, including polyphenols and usnic acid, are responsible for many of these health-supporting benefits.     

The entire herb is considered medicinal and beneficial for various therapeutic purposes.      

Health Benefits of Usnea:

Animal and lab-based scientific research, traditional medicine systems, and contemporary herbalists have observed various benefits of this herb.

Below are the top health benefits of usnea and its main constituents. 

usnea health benefits

1. May have Antimicrobial Benefits

Usnea lichen has been found to have antimicrobial activity.

Infection occurs when bacteria, viruses, fungi, or other microbes invade the body. The immune system responds to these conditions by attacking and eradicating foreign invaders. Using antimicrobial herbs is a great way to support your body’s natural defenses.

A review mentions that this herb has significant antimicrobial activity against various bacteria and fungus strains. It was also found to have slight antiviral activity.

While multiple lab-based studies have observed usnea’s antimicrobial activity, few human or animal trials have been conducted. However, many traditional accounts mention its ability to eradicate bacterial, viral, and fungal infections.    

A comparative lab-based study found that this herb was effective against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The researchers noted that certain types of extracts were more effective than others.

Another lab-based study discovered that usnic acid, a lichen secondary metabolite found in usnea, can potentially prevent biofilm-based wound infections. Researchers found that the usnic acid that usnea contains effectively prevented infections from gram-positive bacteria when used in topical wound dressings.   

In a third lab-based study observing usnic acid, researchers discovered that the constituent has antibacterial properties against various bacteria strains, including S. Epidermidis, E. Faecalis, B. Cereus, and S. Pyogenes. The results also showed that the usnic acid did not damage healthy cells.

The American Botanical Council writes that usnic acid blended with Licorice (Glycyrrhiza glabra) has an antibacterial effect against the bacteria that causes acne. 

Prominent herbalist, Rosemary Gladstar, mentions that this herb has “antibiotic” properties, which make it helpful “for treating urinary and bladder infections, cystitis, and fungal infections.” 

Herbalist Christopher Hobbs suggests using usnic acid for bacteria and fungal infections. He writes that usnic acid plays a prominent role in usnea’s antimicrobial effects by disrupting cellular metabolism in bacteria and fungus. Christopher Hobbs also notes that “usnic acid is more effective against some bacterial strains than penicillin.”

David Hoffmann, a registered herbalist of the AHG, suggests that usnic acid “demonstrates strong antibacterial activity, especially against the tuberculosis bacterium, Mycobacterium tuberculos”.


Lab-based research has found that usnea may be able to effectively inhibit bacteria, viruses, fungi, or other microbes, although human clinical studies are needed to verify these findings.

2. May Have Anti-Cancer Effects

Various lab-based studies suggest that usnea and its active constituent, usnic acid, exhibit anti-cancer properties. 

It should be noted that no human clinical trials have been conducted and effectiveness has not been proven. However, the initial findings listed below are promising from a research standpoint.

Cancer occurs when there’s overgrowth and spread of cancerous cells. These cells grow and disrupt normal organ functioning. This disruption often leads to detrimental health problems or death.

In a lab-based study observing usnea and usnic acid, researchers noticed that usnic acid has significant cytotoxic activity on tumor cells. These results suggest that usnic acid shows promising potential for anti-cancer therapy.

A comparative lab-based study discovered that usnic acid shows strong anti-cancer activity against human skin cancer cells. 

In a lab-based study observing cervical cancer cells, researchers discovered that usnic acid inhibits the growth of tumor cells. The usnic acid also caused cell death in the cancerous cells. 

Another study involving gastric cancer cells found that usnic acid prevents cancer cell growth and causes cell death. Researchers noted that this effect of usnic acid was dose-dependent, meaning the larger the dose, the more effective the treatment.

An active constituent of Usnea longissima (a cousin with similar chemical components) called barbatic acid demonstrated anti-cancer activity in a lab-based study. The barbatic acid extract increased the rate of naturally occurring cell death in cancerous cells.


Lab-based studies indicate that usnea may work to inhibit and prevent the growth of cancer cells. Human trials are required to test the efficacy and safety of this finding.

3. May Have Antioxidant Properties

Research shows that one of usnea’s active constituents exhibits antioxidant effects.

Antioxidant molecules support the neutralization and eradication of free radicals. Antioxidants have demonstrated the ability to reduce stress, support healthy aging, and benefit overall health. 

A lab-based study observing usnea’s active constituents found that usnic acid has the highest antioxidant activity. This usnic acid extract may help to reduce levels of free radicals, which cause physical stress and speed up aging.

Another study on usnea’s active constituents discovered that usnea contains antioxidant activity when extracted in acetone, ethanol, and water. Researchers mention that antioxidant levels varied with each solvent and that acetone was the most potent extraction.


Research shows that usnea may possess antioxidant activities, but human clinical studies are needed in order to confirm this finding.

4. Other Potential Benefits

Other purported usnea benefits include: 

  • May Support Digestion: Rosemary Gladstar suggests the bitterness of usnic acid for soothing the stomach and enhancing healthy digestion. Christopher Hobbs writes that this herb was traditionally used for stomach weakness, implying that the herb may prevent vomiting.  
  • May Encourage Wound Healing: An animal study observing skin wounds found that usnic acid supports faster wound healing. Researchers note that usnic acid’s anti-inflammatory properties may be responsible for this effect.     
  • May Stop Excess Bleeding: Herbalist Henriette Kress and botanist Dr. John Hill, writer of The Family Herbal(1812),  suggest using usnea to stop blood flow and ease heavy menstruation. 


Usnea has been tied to a wide variety of health benefits. Human clinical trials are needed to verify these findings.
4 benefits of taking usnea

Usnea Herb Safety:

Safety Class: 1

Interaction Class: A

In general, this herb is well tolerated and safe to take for most individuals.

Usnea is generally recognized as safe (GRAS) by the FDA. 

The Botanical Safety Handbook mentions that although some cases have reported liver toxicity, there is no official scientific evidence that usnea can cause liver damage.

Pregnancy & Lactation:  

It is not recommended to use usnea during pregnancy and lactation due to a lack of data, according to the Botanical Safety Handbook.


Standard dosing for usnea is as follows:

Decoction (tea): Add 1 cup of water to 1 teaspoon of dried herb and bring to a boil. Reduce to a simmer and cover for 30 minutes. Remove from the heat and let stand for 15 minutes. Drink 1 cup, 3x per/day.

Tincture (1:5): 3-4ml, 3x/day.

Fluid Extract (1:1): 1-2ml, up to 3x/day.

Dietary Supplement: 60–120mg/day.


Usnea is not on the United Plant Saver’s “at-risk” list and is considered minimally impacted by human activities.

Naming & Taxonomy:

Usnea’s scientific name is Usnea barbata. It is popularly known as “Old Man’s Beard,” and its medicinal use dates back thousands of years in Asia, Africa, and Europe. 

This herb’s name comes from the Arabic word “usna,” meaning moss. The Latin term “barbata” refers to the appearance of this herb and means “bearded.” Usnea is classified as lichen, which is a symbiotic species of fungi and algae.

Usnea grows slowly year-round in temperate forests. It belongs to the Usneaceae family and “drips” from tree branches. Traditional accounts mention that several lichen species go by the name “old man’s beard”; however, only the usnea lichen species carry medicinal properties. 

The usnea species is native to many places globally, including Europe, Africa, Asia, and New Zealand. The characteristic pale green network of fibrous strands grows in moist conditions. This herb is especially sensitive to air pollution.

Usnea’s strands are round and can grow up to 20cm long in ideal environments. They play an important role in forest ecosystems, providing shelter and food for smaller invertebrates. Usnea also helps cycle carbon between plants, animals, and the atmosphere.

This herb is considered a “parasitic” species that feeds off the host tree. It grows on pesticide-free fruit trees, oaks, pines, and Douglas firs.     

There are around 600 species of usnea. Many contain similar active constituents and therapeutic properties to this usnea species.    

Common names of usnea include: Beard Lichen, Beard Moss, Old Man’s Beard, Usnea Lichen, Woman’s Long Hair, Beard Lichen, Trees’ Dandruff, Bear’s Beard, Beard Moss, Oak Moss, Tree Moss, Song Luo (Chinese).

Other species of usnea include: 

  • Usnea australis
  • Usnea dasypoga
  • Usnea florida
  • Usnea hirta
  • Usnea rubicunda
  • Usnea rubiginea
  • Usnea scabrida
  • Usnea subfloridana

History & Traditional Use:

Usnea can be traced back to many ancient cultures, including Greek, Egyptian, Chinese, African, and Native American. The Greek physician, Hippocrates, wrote about using this herb for urinary complaints around 400 BC. 

In the 19th century, travelers found lichen remains undisturbed in an ancient case. Evidence shows that the usnea was around 3000 years old and dates back to ancient Egypt, around 1700-1600 BC. 

The early medicinal uses of usnea stem from the “Doctrine of Signatures,” which evolved from the idea that the Gods created plants to resemble body parts they supported. Various cultures associated the appearance of lichen with lung tissue (network of veins) and hair, meaning it helped lung and hair conditions.    

Before the 1700s, herbalists labeled lichen as moss. Along with usnea’s various medicinal uses, cultures also use lichen as a dye for textiles. Surprisingly, this herb produces an orange color when used as a dye.

Presently, this lichen is a prized herb used across the globe for industrial and medicinal purposes. 


Usnea is a highly-beneficial herb that impacted many ancient cultures for thousands of years and has recently gained traction in the contemporary herbal scene.

While there are numerous clinical trials on usnea and its active constituents, more research is needed to understand and verify usnea’s full therapeutic potential. 

It is important to consult a healthcare provider if you’re considering the addition of an usnea dietary supplement or herbal preparation. Proper species identification is essential if you choose to wild-harvest this herb.     

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About Siobhan Mendicino

Siobhan is a herbal researcher and writer. She has a bachelor of science in communications as well as having completed a post-baccalaureate certificate in herbal studies.