In a study “Efficacy and Tolerability of a Standardized Willow Bark Extract in Patients With Osteoarthritis: Randomized, Placebo-Controlled, Double Blind Clinical Trial,” Schmid B, Ludtke R, et al, Z Rheumatol (2000;59:314-320), willow bark extract was compared to placebo in a group of arthritis patients. In the study, 39 subjects were given willow bark extract (standardized to 240 mg. of salicin/day) and 39 subjects were given a placebo. The subjects receiving the willow bark experienced an improvement of symptoms (14%) for pain evaluated by the WOMAC Osteoarthritis Index and the placebo group had a 2% increase in the pain score.