Comfrey Leaf Extract 1 oz. by Best Botanicals. Save 10 Off!. $9.00. The Comfrey Leaf Extract traditional uses are for treating damaged muscles and broken bones, The leaf tea can help inflamed, ulcerated digestive tracts and coughs. The leaf poultices historically used to reduce swelling and bruising around sprains, arthritic joints, speeds healing of cuts, burns, open sores, and eczema.