Comfrey Leaf and Herb Profile
Also known as
Symphytum officinale, Bruisewort, Knitback, Knitbone, Boneset, Slippery Root, Bruisewort, Ass Ear, and Blackwort.
Comfrey's use in Chinese traditional medicine spans over 2000 years. All Materia Medica from the Middle Ages forward carried descriptions on the uses of comfrey. Comfrey baths were very common during the Middle Ages. Comfrey is widely known as "one of nature's greatest medicinal herbs", and has appeared in the U.S. Pharmacopoeia, as well as in herbals and compendiums around the world. Recently, reports of the toxic effects of pyrrolizidine alkaloids in comfrey have led some herbalists to be wary of using it internally. PAs in extremely large doses or over long periods of time may cause potentially fatal damage to the liver. Many leading herbalists and traditional healers question the warnings, pointing to laboratory tests that show only minute levels of PAs in random samples of comfrey preparations.
tannin, rosmarinic acid, allantoin, steroidal saponins, mucilage, inulin, pyrrolizidine alkaloids, Gum, Carotene, Glycosides, Sugars, Beta-sitosterol, Triterpenoids, Vitamin B-12, Protein, Zinc. The main healing ingredient in comfrey leaf appears to be a substance called allantoin, which encourages the rapid growth of cells.
Paste, ointment, tincture, decoction, poultice and in cosmetics.
With regards to the warnings that comfrey can cause cancer and liver disease, most herbal practitioners point out that those results were from studies that isolated the pyrrolizidine alkaloids and fed or injected them into animal subjects in doses far higher than any typical usage of comfrey leaf, and that comfrey leaf has been regularly ingested by thousands of people around the world without reported ill effects.
Not recommended for internal use. Not to be used while pregnant. Not to be applied to broken or abraided skin. Comfrey was widely used and recommended until the mid-1980s, when reports began to surface about the possibility of liver damage from the pyrrolizidine alkaloids that some plants contain. In 2001, the FTC and FDA combined to issue an injunction against products containing comfrey that were meant for internal use. This view has been countered by herbalists, who state that common comfrey, the plant most often used for medicinal purposes, contains only negligible amounts of those alkaloids. In fact, one laboratory study of three different sources of comfrey found no pyrrolizidine in one sample, and only negligible amounts in the other two. Still, many herbalists recommend that comfrey preparations should not be taken internally because of the possibility of liver disease and damage. Comfrey should also not be used by pregnant or nursing women.
This information is not intended to diagnose, treat, cure, or prevent any disease.