Hydrocortisone. Molecular model of the steroid hormone hydrocortisone (C21.H30.O5), also known as cortisol. This hormone is produced by the adrenal gland. Its functions include triggering increases in blood sugar, immune system suppression, and fat, protein, and carbohydrate metabolism. It is administered as a drug to treat deficiencies of this hormone. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white) and oxygen (red).