This book explores the medicinal applications of natural-origin drugs, emphasizing their occurrence, distribution, isolation, and identification. It delves into the therapeutic properties and pharmaceutical uses of phytoconstituents, along with the biological sources and chemical compositions of key crude drugs. Readers will gain insights into quality control standards, alternative medicine systems, and the role of herbs in nutraceuticals and cosmetics. Designed for students, researchers, and professionals, this book provides a comprehensive understanding of natural drug substances, their efficacy in treating ailments, and their applications in health and wellness industries, bridging traditional knowledge with modern scientific approaches.