Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study Sigrun Chrubasik, MD, Elon Eisenberg, MD, Edith Balan, MD, Tuvia Weinberger, MD, Rachel Luzzati, MD, Christian Conradt, PhD The American Journal of Medicine Volume 109, Issue 1, Pages 9-14 (July 2000) DOI: 10.1016/S0002-9343(00)00442-3
Figure 1 Percentage of patients who were pain free without rescue medication in weeks 1 to 4 in the placebo, and in the low-dose and high-dose willow bark groups. The American Journal of Medicine 2000 109, 9-14DOI: (10.1016/S0002-9343(00)00442-3)