Mullein leaves and flowers are rich in saponins which are thought to be responsible for the potent respiratory benefits of this herb. They also contain mucilage which coats and soothes irritated mucus membranes, whilst their expectorant qualities help to expel congestion from the lungs.
According to research, Mullein is a cross between the demulcents and saponin-bearing expectorants, which makes it effective in alleviating conditions such as bronchitis with a persistent cough, dry hacking coughs, whooping cough, colds, flu and sinusitis. The saponins contained in Mullein also exhibit anti-viral properties, further adding to its effectiveness against flu and other complaints caused by viruses.
Mullein can be used to help to detoxify the lungs after quitting smoking. Breathing in steam from its leaves or consuming the tea can help to break up and clear out the tar that has accumulated in the lungs. It can also help to cleanse and soothe the bronchial tubes and strengthen the lungs.