Lipases and Phospholipases are key control elements in mammalian metabolism. They share many common features that set them apart from other metabolic enzyme classes, most importantly their association with biological membranes. Their potential as drug targets for the treatment of metabolic diseases is widely recognized, and the first lipase inhibitor drugs have been successfully introduced. Providing drug developers with a firm foundation for lipase-centered drug design, the editors of this volume have assembled experts from different scientific disciplines to create a comprehensive handbook for all pharmaceutical chemists, biochemists and physiologists working with lipases. The authors examine fundamental aspects of lipase function in vitro and in vivo, explaining how this knowledge may be used to develop lipase assays. They also treat the physiological roles of lipases in normal and disordered metabolism, as well as strategies to target lipases for the treatment of diabetes, obesity and related disorders. Additional topics include the application of phospholipases for liposome-based drug delivery and their use as diagnostic tools.