Usnea Lichen CO2 Extract – Usnea Barbata Usnea Lichen CO2 Extract (4% Usnic Acids) is obtained from Usnea Barbata using pure and environmentally friendly supercritical fluid (natural Carbon Dioxide) extraction technique. Therefore, Usnea Lichen CO2 Extract contains no solvent residues, no inorganic salts, and no heavy metals. Usnea Lichen CO2 Extract contains antimicrobial usnic acids 3.8% – 4.2% and the antimicrobial activity of usnic acid has been widely documented in the literature against gram positive Staphylococcus and Streptococcus and the fungi Trichophyton and Candida and also against gram negative bacteria. Multifunctional Usnea Lichen CO2 Extract has demonstrated both antimicrobial efficacy and anti-inflammatory characteristics. Additional testing has demonstrated particular efficacy against Staphylococcus aureus, pseudomonas aerugenosa, Escherichia coli, Candida albicans and Aspergillus niger. The highest efficacy was with Staphylococcus aureus and Pseudomonas aeruginosa followed by Candida albicans, Escherichia coli and Aspergillus Niger. Other testing has demonstrated potent antimicrobial activity against Propionibacterium acnes, Corynegacterium pseudodiphtericum and pityrosporon ovale. These bacteria and yeast are typically associated with dermatological problems.