Mullein (pronounced mull in) is a tall, flowering plant that grows in many parts of the U.S. and Europe that has been used in herbal medicine since ancient times. People who have been Simple Ways To Use Mullein For Lung Health Betterbrand The Herb Mullein Should Be In Everything You Smoke Puff Herbals Wellness Influencers Say Smoking Mullein Leaf Is a Lung Cleanse. Doctors Say There's a Much Healthier Alternative.