Potent and selective 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) inhibitor (Ki = 2.3 nM) that displays little activity at 11βHSD2 (1.5% inhibition at 10 μM). Inhibits the conversion of prednisone to prednisolone in human hepatocytes in vitro (EC50 = 15 nM) and has antidiabetic activity in vivo. Orally active.