Many people who become interested in herbs and natural remedies began with an introduction to echinacea, an herbal remedy commonly used for treating colds. Does it really work?

Echinacea is a perennial plant that grows 1-2 feet (0.3-0.6 meters) in height and looks something like a Black-eyed Susan. Grown both commercially and in the wild, its flower, stem, and root are marketed in pill, liquid, or powdered form.