It is widely believed and repeatedly stated that herbal drugs, being natural, are devoid of all toxic or adverse effects. This misconception often leads to the misuse of herbal drugs either independently or in combination with other drugs. This book embodies a survey of about 1500 medicinal plants and herbal products. It includes more than 100 examples of adverse side effects and drug interactions, a review of herbal drugs from 24 countries, and the effects of 72 commonly used Indian medicinal plants and 12 herbal formulations.