Medicinal Uses:
Comfrey is a vulnerary, emollient, demulcent, astringent and expectorant. Although there is much debate about the safety of Comfrey, there is little argument about its capacity to stimulate tissue regeneration. Comfrey is rich in the compound allantoin, which stimulates cell proliferation and is used widely in western allopathic medicine. The safety of Comfrey has come into some debate in recent years. While studies linking internal consumption with cancer have since been discredited, studies that show a possible link to liver damage through Comfrey use are of somewhat more concern .
It has been shown definitively that some varieties of Comfrey (particularly Prickly Comfrey (Symphytum asperum) and Russian comfrey (Symphytum uplandicum) can produce substances that are potentially harmful to the liver (pyrrolizidine alkaloids) when taken internally. However, the amounts of these toxic substances detected in the more common and widespread Common Comfrey (S. officinale) are minute, ranging from small amounts to essentially none.
While a direct cause and effect link between Comfrey and any disease in humans has yet to be established, many countries have placed restrictions on its use or banned it entirely. Some herbalists contend that the dangers of Comfrey are highly overstated, pointing out that in all the years before now, with extensive use as a medicine and a livestock feed, Comfrey has had no ill effects connected with it. Even now, there is no direct link between Comfrey and any health concerns. Present worries are theoretical and based on the toxicity of the abovementioned pyrrolizidine alkaloids.
The German Commission E approves Comfrey for external treatment of injuries such as bruising, sprains and torn ligaments, where no skin is broken. Too bad that Comfrey is the best healing agent that I have seen for cuts and wounds.
Its capacity for healing cuts and wounds is so strong that it is not necessarily good for deeper wounds where you cannot reach to apply the Comfrey fully. It is capable of stimulating healing so much on the surface that it has been known to heal over deeper infections, leading to abscesses. The pulverized and heated root is an excellent poultice for any inflammatory swelling or abscess. As well as stimulating tissue regeneration, it is also effective in destroying bacteria and so speeds the healing of infections.
CAUTION: The safety of Comfrey for long-term external use is now suspect. In particular, species other than the pure strain of the officinalis species may pose risk of liver damage. Not recommend for internal use during pregnancy and nursing. Comfrey is not allowed in food products in Canada.