Thiazolidinediones (TZDs) are a group of structurally related peroxisome proliferator-activated receptor γ (PPARγ) agonists with antidiabetic actions in vivo. Rosiglitazone is a prototypical TZD and has served as a reference compound for this class. Rosiglitazone is a potent and selective PPARγ ligand. It binds to the PPARγ ligand-binding domain with a Kd of 43 nM. It activates luciferase-based expression constructs PPARγ1 and PPARγ2 with EC50 values of approximately 30 nM and 100 nM, respectively. Rosiglitazone is active in vivo as an antidiabetic agent in the ob/ob mouse model, and has been used as an oral hypoglycemic agent in the treatment of Type II diabetes in humans for many years.