Swanson Mullein Leaf Extract capsules contain a standardized 4:1 extract of pure mullein leaf. Dioscorides, the ancient Greek pharmacologist who wrote the original  Materia Medica,  is believed to be the first to employ this herb traditionally used for respiratory support. This remains its primary use today, and herbalists from China to California still recommend it just as Dioscorides did over 2,000 years ago.<br/><ul><li><p>Traditionally used to support respiratory health</p></li><li><p>May help support healthy mucus membranes</p></li><li><p>Source of antioxidants for overall wellbeing</p></li><li>Non-GMO</li><li>Per GMP guidelines set forth by the FDA, most products are formulated for 24 months from the date of manufacture. Liquids and probiotics are formulated for 12 months.</li></ul>