Usnea — what it is and why people use it

Usnea is a stringy, pale green lichen that grows on tree branches and rocks. For centuries people have used it as a natural antiseptic and wound helper. Modern lab work backs some of that: extracts containing usnic acid show antimicrobial activity against certain bacteria and fungi in test-tube studies. That makes usnea useful in topical products like creams, salves, and wound dressings. It is not a miracle cure, but it can be a helpful, natural option for minor skin issues when used properly.

How to identify usnea

If you want to find or recognize it, look for hair-like or beard-like strands hanging from branches. The color is usually pale green to gray. Do the pull test: a true usnea ribbon has a thin, elastic inner core you can see when you gently pull the lichen apart. If it snaps like a twig or has no elastic center, it may be a different species. Usnea is brittle when dry and slightly rubbery when fresh. Never collect lichens from protected areas, and avoid overharvesting; take only small amounts from abundant trees.

Practical uses and what works best

Topical use is the safest and most supported approach. People apply usnea salves for small cuts, scrapes, and mild skin infections. Some throat sprays and lozenges use usnea extracts for sore throats because of its antimicrobial properties in lab tests. Commercial products are preferable to wild-made remedies because they are standardized and tested for contaminants.

Be careful with internal use. Usnic acid, the active compound in usnea, has been linked to liver damage in some reported cases, particularly when taken orally in high doses or in weight-loss supplements. That means you should not take raw usnea or unverified oral extracts without talking to a healthcare provider. If your goal is an internal herbal therapy, look for alternatives with clearer safety profiles and medical support.

Before using usnea on your skin, do a patch test on a small area for 24 hours to check for irritation. If you have a known liver condition, take medications that affect the liver, are pregnant, or breastfeeding, avoid internal usnea and consult your clinician about topical use. If a wound looks infected, has spreading redness, fever, or increasing pain, see a doctor instead of relying on home herbal care.

Sustainability matters. Usnea grows slowly. Buy responsibly sourced products or small amounts from ethical suppliers. Commercial extracts reduce pressure on wild populations and usually come with quality checks.

If you want to try usnea, choose a reputable brand, follow product directions, and keep your healthcare provider in the loop. Used cautiously, usnea can be a useful natural antiseptic on the skin, but it is not a substitute for professional medical care when infections are serious.