what is white willow bark
White Willow Bark What is white willow bark? White willow bark (salix alba) is the source from which aspirin is extracted. It is often used as a natural substitute for aspirin in the treatment of musculoskeletal pain and inflammation, and in the prevention of blood clots.hite willow bark (salix alba) is the source from which aspirin is extracted. It is often used as a natural substitute for aspirin in the treatment of musculoskeletal pain and inflammation, and in the prevention of blood clots.