Figure 2: The metabolic pathway showing the steps involved in the synthesis of cortisol from cholesterol. Cholesterol is converted to pregnenolone by desmolase, which is then converted to progesterone by 3-B-hydroxysteroid. Progesterone is converted to 17-a-hydroxyprogesterone (17-OH progesterone) by 17-hydroxylase. The 17-OH progesterone is then converted to 11-deoxycortisol by the enzyme 21-hydroxylase. Finally, 11-deoxycortisol is converted into cortisol by 11-hydroxylase. DHEA: dehydroepiandrosterone.