Hexose-6-phosphate dehydrogenase (H6PDH) knockout (KO) mice have reduced NADPH generation within the endoplasmic reticulum. As a consequence, 11-hydroxysteroid dehydrogenase type 1 (11-HSD1) enzyme activity switches from a reductase to a dehydrogenase leading to glucocorticoid inactivation. 11-HSD1 has emerged as an important factor in regulating hepatic glucose output; therefore we examined aspects of glucose homeostasis in KO mice. Compared to wild type (WT) mice, KO mice have reduced weight gain, display peripheral fasting hypoglycaemia, improved glucose tolerance and elevated plasma corticosterone concentrations. Plasma insulin levels in fed and fasted KO mice are normal, however insulin and plasma glucose levels are reduced 4 hours after fasted animals are re-fed, indicating improved insulin sensitivity. There is preserved induction and activity of the glucocorticoid responsive gluconeogenic enzymes PEPCK and G6Pase in fasted KO mice. Glycogen storage is elevated in fed KO liver, with fed glycogenesis rates increased in KO mice. There is normal flux of lactate through gluconeogenesis recovered as plasma glucose, coupled with increased glycogen derived from lactate. These data suggest partial retention of glucocorticoid sensitivity at the level of the liver. We therefore postulate that increased glycogen synthesis may reflect increased flux of glucose-6-phosphate (H6PDH substrate) through to glycogen in the absence of H6PDH mediated metabolism.