This book critically examines the science behind aging-modulatory and geroprotector compounds, addressing the growing demand for health-promoting and lifespan-extending supplements. With over 250 compounds listed in various databases, the need for clear, evidence-based guidance is more pressing than ever. This volume fills that gap by evaluating the current state of scientific knowledge on widely used natural and synthetic compounds, biological extracts, and traditional dietary formulations from diverse cultures. Key topics include the evaluation of micronutrients, vitamins, and probiotics as dietary supplements, the role of plant-based compounds in traditional medicinal systems like Ayurveda and TCM, and the distinction between drugs against diseases and those for health. The book also explores synthetic and natural compounds targeting specific biochemical pathways, emphasizing a shift from disease-specific therapies to holistic approaches in longevity medicine. Ideal for biogerontological and medical researchers, healthcare professionals, and students in health-related fields, this book offers a comprehensive review of the latest research and practical insights into supplements and drugs for healthy longevity. It invites readers to consider critical questions about the efficacy and necessity of these compounds in promoting a long and healthy life.