The salicin in White Willow Bark is the foundation from which a variety of modern health and comfort aids have been developed. The herb itself has been used for centuries. Modern herbalists continue to recommend White Willow Bark for its ability to promote joint and muscle comfort without stomach irritation or other concerns common with synthetic products. Our 25% Salicin White Willow Bark Extract delivers a consistent standard dose of salicin, 10% higher than our original formula, for reliable results.