Botanical Overview
Usnea spp., commonly known as Old man’s beard or lichen moss, is a genus of fruticose lichens belonging to the family Parmeliaceae. It is widely distributed in temperate regions worldwide. The medicinally used part is the thallus, which is the main vegetative body of the lichen.
Energetics
Usnea is considered cooling and drying in nature. It has a bitter and acrid taste, with an ascending directionality. It is tonifying in quality and is traditionally associated with the qi aspect in energetic terms.
Primary Actions
- Antimicrobial
- Antibacterial
- Antifungal
- Anti-inflammatory
- Expectorant
Indications
Western
- Respiratory infections
- Sore throat
- Wounds
- Skin infections
- Cough
- Tuberculosis adjunctive treatment
Syndromes
- Upper respiratory tract infections
- Chronic bronchitis
- Fungal infections
TCM
No well-established traditional Chinese medicine indications documented.
Ayurveda
No established Ayurveda indications found.
Unani
No established Unani indications found.
Constituents & Mechanisms
Key phytochemicals include usnic acid, polysaccharides, and various phenolic compounds responsible for its broad-spectrum antimicrobial and anti-inflammatory effects.
Dosage & Preparations
- Tincture (1:5, 40% ethanol), 2-5 mL taken 2-3 times daily
- Infusion of 1-2 g dried thallus in 150 mL water, taken twice daily
- Topical applications such as poultices or washes for wounds and skin infections
Safety & Contraindications
Usnea is generally safe when used appropriately but should be avoided during pregnancy and lactation due to insufficient safety data. Isolated usnic acid has been associated with hepatotoxicity at high doses; caution is advised especially for individuals with liver disease. Allergic reactions may occur in sensitive individuals. There are potential interactions with other hepatotoxic drugs, but no well-established interactions are known.
Astrological Correspondences
No authoritative sources found confirming planetary or elemental rulers for Usnea spp.
Selected References
- Plants for a Future Database – Usnea spp.
- Usnic Acid: An Antimicrobial Lichen Metabolite with Potential Clinical Utility
- EMA Assessment Report on Usnea spp.