Comfrey ointment is a traditionally nourishing balm for the skin and beyond. Comfrey is also referred to as knitbone. Comfrey conains an ingredient called allantoin, which is said to aid the regrowth of skin, along with rosmarinic acid and tannis. Studies have shown that comfrey may inhibit the shrinkage of collagen matric. Never use comfrey on deep wounds or wounds that could have infection, due to the super healing effect.