Cortisol, known as hydrocortisone when used as a therapeutic, is a glucocorticoid produced by the adrenal cortex in response to adrenocorticotropic hormone (ACTH).^1,2 It is an agonist at the mineralocorticoid receptor (MR) and the glucocorticoid receptor, with an approximately 6- to 10-fold greater affinity for MR. Cortisol production is increased during periods of stress, and it is a major effector molecule in the hypothalamic-pituitary-adrenal axis (HPA) stress response.² Cortisol levels increase with age and are often elevated in major depressive disorder, certain forms of hypertension, and Parkinson’s disease.^3,4,5