Comfrey root and leaf have been used since Roman times, dating back thousands of years. This herb has been utilized in folk medicine throughout Europe and North America and has been widely cultivated as a garden medicinal specifically for its reputation for healing various internal and external wounds. Much debate surrounds the safety of comfrey due to various parts and preparations containing potentially toxic alkaloids. It is important to understand that the part used, species, and time of harvest all come in to play when determining the safety of this herb. A large body of traditional use supports its safety and efficacy if used intelligently and cautiously.
HISTORY AND FOLKLORE: Comfrey’s attributes were mentioned by many of the herbalist-alchemists of old such as Dioscorides (a Greek physician pharmacologist and botanist, practicing in 1st century Rome) and Paracelsus (a 15th century Swiss Renaissance physician, botanist, alchemist, and astrologer).5 It was recommended for wounds by St. Hildegard of Bingen, a herbalist and nun born in 1098 C.E. It was cultivated in gardens for centuries, its popularity giving rise to myriad common names. Many references were made to comfrey’s healing properties in various herbals in the 16th and 17th centuries.
Traditionally in Europe, the root and leaf were used in cases of sprains or strains or broken bones. Due to the roots high mucilage content, it was often utilized in the same way as marshmallow root (Althaea officinalis).2
The root is considered nutritive, cooling, and moist in traditional Chinese medicine (TCM).9 It is a yin tonic that has been utilized for wounds, however when there is concern about the pyrrolizidine alkaloids contained in the root, often Rehmannia glutinosa is substituted as it has similar energetics.9
Comfrey root is a source of the constituent, allantoin, which is a cell proliferant used in many cosmetic and dermatological preparations, although allantoin can also be derived from several other natural sources (including mammal urine) and is made synthetically as well.