Roots and bark are used. It contains Berberine that may be a cause of gastritis, nephritis, phototoxicity and severe jaundice by displacement of albumin -linked bilirubin: higher risk of kernicterus to newborns, which is greater in cases of 6-Glucose-PD deficiency. It is popularly widely used, however, its effectiveness has not been shown. Use not approved by the Commission E of German Ministry of Health. It should be avoided.