Comfrey root: from tradition to modern clinical trials.

Comfrey (Symphytum officinale L.) has been used over many centuries as a medicinal plant. In particular, the use of the root has a longstanding tradition. Today, several randomised controlled trials have demonstrated the efficacy and safety. Comfrey root extract has been used for the topical treatment of painful muscle and joint complaints. 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. This paper provides information on clinical trials, non-interventional studies and further literature published on comfrey root till date.