White Willow Bark ExtractDESCRIPTION Standardization: 15% Salicin Ratio: 14: 1 Botanical Name: Salix alba L. The underside of the leaves have a distinctive white tone which is the origin of its name. In 1829 its main active ingredient, salicin, was identified and resulted in the creation of the pain killer acetyl salicylic acid (ASA) years later. The use of Willow dates back 6000 years. Ancient civilizations used White Willow Bark Extract for conditions associated with pain