Pregnenolone is biochemically a prohormone. It is made directly from cholesterol within the mitochondria of the adrenal glands and, to a lesser degree, the nervous system, with the help of the cholesterol side chain cleavage enzyme. Pregnenolone is a precursor to various hormones, such as progesterone, mineralocorticoids, glucocorticoids, androgens, and estrogens. So it can help the body maintain normal hormone levels, which in turn helps numerous body functions.