• Substance S) Cortexolone or cortodoxone or 11-deoxycortisol or 11-desoxycortisol or 11-deoxyhydrocortisone or 11-desoxyhydrocortisone or Reichstein's Substance S or, most commonly, Compound S, is a steroid that can be oxygenated to cortisol (hydrocortisone). (freecollocation.com)