Corticosterone is a 21 carbon steroid hormone of the corticosteroid type produced in the cortex of the adrenal glands. In many species corticosterone is the principal glucocorticoid, involved in regulation of fuel metabolism, immune reactions, and stress responses.

However, in humans, corticosterone is produced primarily in the zona glomerulosa of the adrenal cortex. It has only weak glucocorticoid and mineralocorticoid potencies in humans and is important mainly as an intermediate in the steroidogenic pathway from pregnenolone to aldosterone.