Bioenhancers have been used in Ayurveda historically and are now being investigated for their pharmacological effi cacy. Herbal bioenhancers work on the gastrointestinal tract to improve absorption and drug bioavailability by acting on the drug metabolic process. Many herbal drugs show low activity due to their poor lipid solubility or improper molecular size. Piperine, gingerol, naringin, quercetin, niaziridin, glycyrrhizin, allicin, curcumin, genistein and others are able to enhance the bioavailability of active pharmaceuticals. This book details various facets of herbal bio-enhancers in a single comprehensive text.