This book focuses on efficacy, toxicity, drug interactions, and abnormal clinical laboratory tests resulting from the use of herbal remedies. Although a few herbal remedies are safe and have efficacy (for example saw palmetto), many herbal remedies are toxic. This book guides in the interpretation of abnormal test results in otherwise healthy subjects due to use of herbal remedies. Chapters focus on interactions between herbals and pharmaceuticals, sources of contamination in herbal supplements, and analytical techniques used in the investigation of herbal remedies.