Comfrey can help to relieve pain, reduce inflammation of muscles & joints, and even speed the healing of bruises. This is because Comfrey contains an ingredient called allantoin, which aids the regrowth of skin, along with rosmarinic acid and tannins. This is why Comfrey may help wounds heal faster.
A large review released in 2013 about the medicinal uses of comfrey stated: It is clinically proven to relieve pain, inflammation and swelling of muscles and joints in the case of degenerative arthritis, acute myalgia in the back, sprains, contusions and strains after sports injuries and accidents, also in children aged 3 years and older. Scientific evidence backs this statement up.