Type 2 diabetes mellitus is a metabolic disease resulting in raised blood sugar which, if not satisfactorily controlled, can cause severe and often debilitating complications. Unfortunately, for many patients, the existing therapies do not give adequate control. Glucagon-like peptide-1 (GLP-1) is an incretin hormone which has a spectrum of activities which oppose the symptoms of diabetes. Of particular significance is the fact that these actions are glucose-dependent, meaning that the risk of severe hypoglycemia is practically eliminated. The recent elucidation of the key role of dipeptidyl peptidase IV in determining the metabolic stability of GLP-1 has given the rationale for two novel therapeutic strategies, namely, GLP-1 analogs which are resistant to the enzyme and inhibitors of the enzyme which boost levels of endogenous intact GLP-1. These approaches aim to maximize the therapeutic advantages offered by GLP-1 and give the hope of providing effective glycemic control without the risk of overt hypoglycemia.