Usnea: Its History, Health Benefits, Uses, and Side Effects

Published on April 24, 2023

By Lisa Stockwell

Lisa Stockwell

Lisa Stockwell has worked as a copywriter, writer, author, and editor for 35 years, specializing in the field of healthcare since 2009. She recognized the need for reliable health information while supporting friends through unique health challenges and refocused her career to bring clarity and compassion to healthcare communications. Lisa is a graduate of the University of California, Berkeley and a lifelong Northern Californian.

Mushrooms get all the attention when it comes to fungi and their healing benefits. But don’t ignore lichen. Lichens are a type of living thing, made up of two different organisms that work together. One organism is a type of fungus, and the other is a type of alga. Together, they form something that looks like a plant, but it's actually two organisms living and working together as one.

Lichen plays an important role in the health of our planet, converting carbon dioxide in the atmosphere into oxygen. Practitioners of traditional medicine have also long believed that certain types of lichen are invaluable for personal health.

Usnea, REF#1434 commonly called Old Man’s Beard, is a lichen with long, hair-like growth that can be taken as an herbal supplement to promote a healthy immune response. It is also used in a number of cosmetic preparations as a preservative due to its antimicrobial activity. 

As you build your knowledge of herbs and their various health benefits, add Usnea to your list as one with the potential to support your health naturally.

An Introduction to Usnea

As mentioned above, lichen is composed of layers of fungus and algae. This unique collaboration supports the health of the entire organism. The fungus offers the alga a structure to live on, and the alga provides food for the fungus. 

There are several different types of lichens — crustose, fruticose, and foliose — each with its own unique growth form. Usnea is a fruticose lichen, a three-dimensional organism with fungal filaments called rhizines that attach to their substrate with hair-like, shrubby, or cup-like growths.

Usnea has hair-like strands that hang from tree trunks and limbs in moist, cool forests all over the world. In the United States, it’s most common in the Pacific Northwest. 

Ancient Greeks, Native Americans, and traditional Chinese medicine practitioners used Usnea to support respiratory, digestive, kidney, and urinary tract health. Today, over 360 species of Usnea have been identified, and around 20 species are being used in alternative medicine worldwide. 

Lab studies indicate that there are three active ingredients in Usnea — usnic acid, polyphenols, and depsides — that are key to providing the lichen’s beneficial properties.REF#1435 Since most research on Usnea has been limited to lab studies, human clinical studies are needed to determine efficacy, dosages, and safety. 

The Health Benefits of Usnea

Usnea offers a wealth of beneficial compounds that may support overall wellness:*

  • Polyphenols, including flavonoids and lignans, are antioxidants that protect the body from damage caused by free radicals. Free radicals are unstable molecules that cause damage at the cellular level. Polyphenols also have anti-inflammatory properties that may reduce inflammation in the body.
  • Polysaccharides are critical as an energy source to support immune health and normal, healthy cell growth.*
  • Triterpenes support a normal inflammatory response.

Support Healthy Weight

While more studies are needed, Usnea may also have the potential to regulate lipid metabolism and support a healthy weight.REF#1443 While it has been used in weight loss supplements, high doses have caused cases of liver toxicity. It is therefore not recommended for this use except under the direction of a healthcare professional.

How to Use Usnea for Immune Support

Usnea is typically available as an extract or tincture, but it can also be used as a tea and skin cream. It is often mixed with other herbs that support the immune system. For instance, Gaia Herbs offers a blend of Usnea and Uva Ursi with Echinacea and Feverfew to promote urinary tract health.

While Usnea can be harvested for tea, it is not very water-soluble, and it will be less effective in this form.REF#1444 

If you are foraging for Usnea for personal use, be aware that it’s slow growing and at risk of being over-harvested. To avoid depleting the supply, harvest it sustainably by only taking Usnea from tree limbs that have fallen to the forest floor. Only take as much as you need. 

It’s best to purchase Usnea tincture from a trusted online shop that uses sustainable harvesting methods and has been verified by third-party organizations or experts in the field. This will ensure that you are getting responsibly harvested, high-quality Usnea with accurate dosing information and instructions on how to take it safely and effectively. 

Side Effects of Usnea

While Usnea is generally considered safe, with a long history of use in traditional medicine, no human studies have been done to determine proper dosages or the safety of long-term use. Consult with your healthcare professional before taking Usnea to avoid any possible interactions with medications you may be having. 

You should be aware of several potential side effects of Usnea:

  1. Allergic Reactions: Some people may be allergic to Usnea, particularly those who are allergic to other types of lichen, fungi, or mushrooms. Allergic symptoms may include itching, respiratory issues, swelling of the mouth or throat, or hives.
  2. Digestive Issues: Especially in high doses, Usnea may cause digestive issues such as nausea, vomiting, and diarrhea.
  3. Liver Damage: Usnea contains usnic acid, which can be toxic to the liver in high doses. 
  4. Pregnancy and Breastfeeding: There is not enough research on the safety of Usnea during pregnancy and breastfeeding, so do not take it if you’re pregnant or breastfeeding.

    Other Supplements That Provide General Immune Support

    While Usnea is prized by herbalists and traditional healers, you might want to take a different supplement for general immune support. Gaia Herbs offers a selection of options to maintain good health naturally:

    These herbs have their own guidelines separate from Usnea, so make sure you do your research before taking them. 

    If you have questions about what supplements will help you thrive, talk with your healthcare provider, or check out our Matchmaker Quiz to discover the right herbs for you


    • 1. Asghar Sepahvand et al.,, "Usnea sp.: Antimicrobial potential, bioactive compounds, ethnopharmacological uses and other pharmacological properties; a review article", Journal of Ethnopharmacology, March 25, 2021.
    • 2. Prateeksha, B. S. Paliya et al.,, "The genus Usnea: a potent phytomedicine with multifarious ethnobotany, phytochemistry and pharmacology", RSC Advances, Issue 26, 2016,.
    • 3. Jiali Zhu et al.,, "Studies on the regulation of lipid metabolism and the mechanism of the aqueous and ethanol extracts of Usnea", Biomedicine and Pharmacotherapy, August 16, 2017.
    • 4. Violeta Popovici et al.,, "Antioxidant and Cytotoxic Activities of Usnea barbata (L.) F.H. Wigg. Dry Extracts in Different Solvents", Plants, May 2021,.