J Uy, L Fogelfeld, Y GuerraDivision of Endocrinology, Diabetes and Metabolism, John H Stroger Jr Hospital of Cook County, Chicago; Department of Endocrinology, Diabetes and Metabolism, Rush University Hospital, Chicago, IL, USAAbstract: We have now at our disposal the new rapid-acting insulin analogs, of which insulin lispro was the first to become commercially available. While the differences in pharmacokinetic and pharmacodynamic characteristics are indisputable, the clinical benefits attained by these changes have not been as clear. In the present review, we discuss the structure, pharmacology, and landmark studies related to insulin lispro. The clinical characteristics of insulin lispro are compared with those of insulin regular and other insulin analogs in different clinical situations. Also included are the aspects of quality of life and cost-effectiveness that may modify the modern practitioner's decision to adopt one type of insulin over another.Keywords: insulin lispro, rapid-acting, insulin, analog