Solaray Mullein Leaf provides powerful, soothing support for your overall wellness. Solaray True Herbs Mullein 330mg delivers a potent dose of this traditional herb. While clinical studies are needed to confirm mulleins benefits, the herb has traditionally been used for respiratory support. Mullein contains large amounts of mucilage, a gelatinous soluble fiber thought to be the source of the botanical's soothing effects. Like all Solaray products, Mullein is lab verified for potency, purity, and identity.