Praised for centuries by herbalists throughout the world, who still use it to treat disorders ranging from cuts to cancer, comfrey nevertheless is rejected by many practitioners in the United States as too dangerous for any type of internal use. Comfrey contains pyrrolizidine alkaloids, which can cause liver damage when consumed in large amounts. The active agent in comfrey is allantoin, which fosters the growth of new cells. Although the dried roots and leaves are used for medicinal purposes, the comfrey root contains up to twice as much allantoin as the other parts. While its internal use remains questionable, comfrey can be used safely on external injuries such as cuts and other wounds.
Over the counter:
Available in tincture, capsules and in bulk.
Tea: 1 cup boiling water poured onto 1 to 3 tsp. dried flowers or leaves and steeped for 10 minutes. Consumed as hot as possible.
Compress: A pad soaked in a coltsfoot infusion for several minutes, wrung out, and then applied to the affected area.
Combinations: For coughs, coltsfoot is often combined with white horehound and mullein; for bronchitis, coltsfoot is mixed with garlic or echinacea.