Comfrey is a perennial shrub that is native to Europe, and its roots and leaves are sold as ointments, compounds oils, creams, compresses and leaf extracts for a variety of medicinal purposes. Comfrey was historically used orally to treat gastrointestinal illness, bronchitis and peptic ulcers, however comfrey has been found to be toxic to the liver when taken internally, and may cause hepatoxicity. As such, oral use of comfrey has been banned in North America and the UK and comfrey is currently only sold for topical purposes.
Beneficial Compounds in Comfrey
Comfrey contains minerals, vitamins and numerous phytochemicals, which are potent antioxidant compounds found in plants. The leaves and roots contain the phytochemicals allantoin and tannins, which both help new skin cells to form and they thereby promote wound healing and healthy skin. Comfrey leaves and roots also contain rosmarinic acid, which is a phytochemical that helps to reduce inflammation.
List of Topical Benefits
Comfrey is used topically to reduce the inflammation of, and promote the healing of, strains, fractures, pulled muscles and broken bones, states the University of Maryland Medical Center, or UMMC. It is also used to reduce the pain and inflammation associated with osteoarthritis. According to Phyllis Balch in her book "Prescription for Nutritional Healing," comfrey helps to speed the healing of various skin conditions including skin rashes, sunburns, dermatitis and psoriasis. Comfrey is also used for the treatment of bedsores, bites and stings, bruises, inflamed bunions, burns, dry skin, leg ulcers, nosebleeds and scabies.
The benefits of topical applications of comfrey are based primarily on anecdotal evidence, and little research has been done to confirm the efficacy of comfrey for its purported uses. A study was done however by the "British Journal of Sports Medicine" regarding the use of comfrey for the treatment of back pain. The study, which was published in the July 2010 issue, concluded that there was a significant difference between the comfrey extract and placebo group regarding pain intensity. In fact, the comfrey extract caused a 95.2 percent decrease in perceived pain during standard movements and it produced the pain-relieving effects rapidly.
Topical use of comfrey is generally considered safe, however substances called pyrrolizine alkaloids are found in comfrey and they can be harmful in large amounts. When comfrey is used on open wound or applied excessively, it can build up in the body and become toxic. As such, UMM states that you should follow the instructions on comfrey products, making sure not to use more then is recommended and not use comfrey for more then 10 days at a time. If you are pregnant or breastfeeding, you should avoid comfrey products altogether.