Sassafras is used externally as a wash for poison oak and insect bites. Taken as a tea, sassafras is used as a diaphoretic during colds and flu and is a traditional "blood purifier" taken in the spring as part of a cleansing program. The root bark provides much of the flavor one associates with root beer, and it is used to form an important part of a traditional root beer brew, along with burdock and other cleansing herbs. As a warming diuretic, it is useful for arthritic and rheumatic conditions.