What Are the Health Benefits of Usnea, and Are There Side Effects?

Usnea is a nutrient-rich herb has been used for centuries as a traditional medicine. The health benefits of usnea include that it may help fight microbial infections, heal wounds, fight cancer cells, and aid in weight loss.

When you are walking through the woods, if you ever come across what appear to be long, green, fuzzy strings hanging from a tree, chances are good that it is a lichen such as Usnea. 

This nutrient-rich herb has been used for centuries as a traditional medicine. However, many of its reported health benefits are not backed by research. Additionally, some Usnea compounds can cause severe side effects when taken orally. Read on to learn more, and before adding any Usnea products to your routine, consult your doctor.

Usnea is a type of lichen that grows on rocks, bushes, soil, and the bark or branches of trees, especially pine trees. It's found in many different regions that have a humid or temperate climate. 

If you look at lichens like Usnea, they may seem like a single plant species, but in reality, they're formed by a combination of algae and fungus that grow together, with the algae providing nutrients and the fungi providing structure and protection.

Usnea lichen looks like long, tangly grayish-green masses of hair, which is why this lichen is commonly compared to an "old man's beard". Around the world, people also call these lichens:

• Tree moss
• Beard moss
• Bear’s beard
• Beard lichen
• Trees’ dandruff
• Woman’s long hair

The genus Usnea belongs to the Parmeliaceae family, with about 600 closely related lichen species growing worldwide. Among them, the most well-known ones are:

• Usnea articulata
• U. australis
• U. barbata
• U. ceratina
• U. dasypoga
• U. filipendula
• U. florida
• U. rubicunda
• U. scabrida
• U. subfloridana

The Usnea herb was often used as a traditional medicine during ancient times. The Greeks used it to treat urinary problems while the Chinese used it to remove phlegm. It was also used in South African folk medicine to treat wounds and inflammation in the throat and mouth.  

Even today, you can find Usnea being used in many herbal teas, tinctures, medical creams, and dietary supplements. Usnea is also added to many cosmetics and personal care products since many of its ingredients have deodorant and preservative-like properties.

Phytochemical studies have found a wide variety of bioactive ingredients in Usnea, including:

• Sterols
• Usnic acid
• Terpenes
• Depsides
• Fatty acids
• Flavonoids
• Depsidones
• Polyphenols
• Benzofurans
• Phenolic acids
• Diffractaic acid
• Norstictic acid
• Polysaccharides

Among them, polyphenols, usnic acid, and depsides are credited for the most health benefits of Usnea. Compounds like benzofurans and depsidones may also have certain medicinal effects. But more research is required to confirm those. 

Usnic acid was first isolated in 1844 and since then, has become the most studied and commercially valued lichen metabolite. It makes up around 1% to 3% of the herb's dry weight. Experts believe that usnic acid protects the plant from the negative effects of the sun's rays and with its bitter taste, deters animals from grazing the plant.

Studies show that usnic acid along with the other active ingredients give Usnea strong antibiotic, antifungal, antiprotozoal, antipyretic, anticancer, antiseptic, antioxidant, antiviral, antiulcer, anti-genotoxic, anti-inflammatory, laxative, digestion stimulating and immunostimulating properties.

For thousands of years, Usnea has been used for different medical purposes. However, current research has found evidence for only a few of them. These are some of those science-backed health benefits of Usnea:

May help with microbial infections. Usnea has long been used in herbal formulas for treating skin infections, urinary tract infections, lung infections, vaginal infections, wounds, colds, and sore throat. Its use as an antimicrobial herb has also been proven by various studies. 

For example, a study done on Usnea barbata found it helpful for stopping the growth of Staphylococcus aureus — a bacteria known for causing skin infections. Usnea extract has also been found effective against many harmful fungi that cause ringworms and athlete's foot as well as fungal imbalances in the gut, mouth, and vagina. 

May help to heal wounds. Studies have found wound healing properties in usnic acid — one of the key active ingredients in Usnea. As per some test-tube studies, this compound can promote wound closure and lower inflammation.

A study done on rats has also found a strong link between usnic acid and a rise in collagen formation — an important marker of wound healing. But more research is needed to confirm if the usnic acid content in skin care products is enough to benefit humans in a similar way.

May help fight cancer cells. There are various bioactive compounds in the Usnea herb that show potent anticancer properties. One among them is usnic acid. Studies show that this compound can kill cancer cells and prevent their growth without affecting the non-cancerous cells. 

Another study done on four different lichens found Usnea intermedia to be a promising solution for cancer treatment. Despite such positive results, more human-based studies are needed to understand the anti-tumor capabilities of Usnea.

May help to lose weight. You may find usnic acid as an ingredient in many fat burners and similar weight loss solutions. Experts believe that this compound aids in weight loss by promoting fat metabolism and a rise in basal metabolic rate. 

However, many such usnic acid-based weight loss supplements have severe adverse effects on the liver. Due to such safety concerns, it's best to avoid weight loss solutions containing usnic acid.

Most side effects of Usnea stem from the oral use of usnic acid. Studies have found that taking usnic acid by mouth increases the risk of severe liver failure, needing an emergency liver transplant, and even death. This is why in 2001, the U.S. Food and Drug Administration (FDA) warned people to stop using a particular weight loss supplement that contained usnic acid because it led to many cases of acute hepatitis, liver failure, and irreversible liver injury.

Another Usnea compound called diffractaic acid has been found to cause liver toxicity when taken in large amounts. 

Rather than taking Usnea by mouth, many experts consider applying its products on the skin to be a safer option. This is because only a minimal amount of usnic will be absorbed by the skin. Even so, Usnea may cause a rash and other allergic reactions.

Due to limited safety research, Usnea is not recommended for women who are pregnant or breastfeeding.

If you wish to use Usnea, try to make a tincture or a salve. 

Since Usnea compounds don't dissolve well in water, you may wish to make a tincture in alcohol. You could also add other immunity-boosting herbs like yerba mansa, echinacea, and osha. Since different Usnea tincture brands have different strengths, though, always follow the guidelines shared by the manufacturers. Avoid using Usnea products for a long time unless you have consulted with your doctor.

To make a Usnea salve, infuse the dried lichen powder into oil and gently heat it for some time until the oil smells like Usnea. After straining, the filtered product can be made into a salve. You can apply this salve on a wound if it isn't infected.