Cortisol or hydrocortisone is the principal glucocorticoid hormone of many mammals including humans. It regulates the glucose metabolism and promotes gluconeogenesis, especially during starvation, and raises blood pressure. Cortisone is an inactive form of cortisol. Related Theory Cortisol is the main glucocorticoid released from the zona fasciculata layer of the adrenal cortex. The hypothalamus-pituitary-adrenal axis regulates both production and secretion of cortisol. Loss of regulation can lead to cortisol excess disorders, such as Cushing syndrome, or cortical insufficiency, such as Addison disease.