This handbook provides key information on the clinical use of nutraceuticals, an increasingly common practice grounded in an understanding of the pharmacological activities of natural compounds and clinical evidence of efficacy and safety. Each chapter examines the effects of nutraceuticals in different therapeutic contexts, including nutraceuticals active on the digestive system, heart, lipid and glucose metabolism, and immune system. The authors also address relevant concerns such as relative and absolute contraindications, range of tested doses (efficacious and safe), possible side effects and pharmacological interactions, and the scientific level of clinical evidence for each product.