Comfrey comes from the Greek word, unite. Europeans in the middle ages called it bone knitter. This beautiful flower originated in Europe. There, it was used to treat a variety of conditions. During the middle ages, young women took baths with comfrey believing it would help restore lost virginity.
Comfrey is a perennial flower. It loves water and marshy areas and grows profusely throughout the British Isles. Both botanical gardeners and herbalists have prized comfrey for its many uses for hundreds, maybe thousands of years. Anyone thinking of planting comfrey in their garden should use lots of nitrogen-based fertilizer or animal manure. This is due to the high needed for nitrogen this plant has.
One species of comfrey, Russian comfrey, is a seedless version. To gardeners, this was a lucky break through because the seedless varieties of this plant grow taller. Bocking is a term of particular interest to the gardening community. In order to grow Russian comfrey, gardeners break off some pieces from the center of the root and place them just below the top of the soil. The original plant recovers in a few weeks, and the broken root sections grow into new plants. This method of farming allows harvest every 5 to 6 weeks. Gardeners should be careful to choose only help the plants to bock, because any plant with rust or mildew will not survive.
Scientific studies confirm the healing properties of this controversial herb. One component, allantoin, has been shown to increase cell growth, which may explain its ability to heal fractures. Other things like skin wounds also benefit from the rapid cell renewal properties of this herb.
There is just one big problem with comfrey—it clogs the liver. The alkaloids contained in the plant have high toxicity causing agents. The FDA issued strong warnings against using the herb internally because several studies showed it caused veno-occlusive disease. As of 2001, there was one death on record in the United States caused by this condition. The lobbyists succeeded in getting the government to refrain from banning it. Now companies sell the herb as a topical supplement, claiming that it will still have the same effects as internal use. No scientific studies have yet been completed to answer this claim.
The benefit to hair and scalp seems to be cell renewal. Some hair loss treatments include this ingredient, claiming it helps improve hair growth. However, there are no studies to back this up. Unless you have a broken bone, I would not recommend this product due to the risk of toxicity.