White Willow Bark

What is white willow bark? There are many different kinds of trees and bushes in Europe, Asia, and some parts of North America that belong to the willow family. White willow, also called European willow (Salix alba); black willow, also called pussy willow (Salix nigra); crack willow (Salix fragilis); purple willow, also called weeping willow (Salix purpurea); and weeping willow are some of the more well-known species (Salix babylonica). Not all willow species possess sufficient salicin for medicinal purposes. In one study, the amount of salicin after 1 and 2 years of growth in the fall and spring varied from 0.8% to 12.6%. Usually, the willow bark sold in Europe and the United States comes from white, purple, and crack willows. People have been using willow bark since Hippocrates' time (400 BC), when he told people to chew on the bark to reduce fever and swelling. Willow bark has been used for hundreds of years in China and Europe to treat pain (especially low back pain and osteoarthri