Note: This review covers salicin-containing species of Salix, which includes Salix alba, Salix fragilis, Salix purpurea, and Salix pentandra.
In the United States, willow bark is used by herbalists as an antipyretic (fever reducer), a mild analgesic (pain reliever), and an anti-inflammatory. There is currently strong scientific evidence that willow bark is effective for osteoarthritis and lower back pain. Early study suggests that willow bark extracts may not be helpful for rheumatoid arthritis, but further study is warranted to confirm these recommendations. Taking willow bark may increase the risk of bleeding; however, this risk may be less than taking aspirin.
Several countries in Europe have approved willow bark for pain and inflammatory disorders. The German Commission E has approved willow bark for fever, rheumatic ailments, and headaches. The British Herbal Compendium indicates that willow bark can be used for rheumatic and arthritic conditions, and fever associated with cold and influenza. In France, willow bark has been approved as an analgesic to treat headache and toothache pain, as well as painful articular (joint) conditions, tendonitis, and sprains. The European Scientific Cooperative on Phytotherapy (ESCOP) has approved willow bark extract for the treatment of fever, pain, and mild rheumatic complaints.