Pregnenolone is often referred to as the “grandparent” of steroid hormones in mammals. Pregnenolone is made from cholesterol in the adrenal glands and to a lesser extent in the brain, liver, skin, testes and ovaries. Once synthesized, pregnenolone is converted to DHEA or to progesterone. Progesterone is used to make cortisol, aldosterone, androstenedione, estrogen, and testosterone.