The leaf and root of comfrey have been employed medicinally for centuries. Originally from Europe and western Asia, it is now also grown in North America.
Comfrey has a long history of use as a topical agent for treating wounds, skin ulcers, thrombophlebitis, bruises, and sprains and strains. Comfrey was used by herbalists to promote more rapid repair of broken bones, hence the common names boneset and knitbone. Topically, comfrey was also used to treat minor skin irritations and inflammation. It has also been used as a wash or topical application for eye irritations and for treating conjunctivitis. Internally, it was used to treat gastro-intestinal problems, such as stomach ulcers, and lung problems.
What it does
Comfrey contains many compounds including allantoin, mucilage and pyrrolizidine alkaloids. It has anti-inflammatory, soothing and potent healing properties.
Recent research has discovered that pyrrolizidine alkaloids may have a negative effect on the liver. It is therefore recommended for external use only. The homoepathic versionof comfrey called symphytum is a safer alternative.
Generally, there are no side effects or contra-indications from using comfrey externally.
At the time of writing there were no well known negative drug interactions with comfrey.