Pregnenolone is the precursor to all natural steroids: the body naturally produces large amounts of this hormone.  Pregnenolone is called the king of the hill because it is the first steroid hormone produced from cholesterol and sits in the key position (on top of the hill), ready to be to be made into any of the other steroid hormones such as DHEA, progesterone, the estrogens (estrone, estradiol, estriol), testosterone, corticosteroids, and aldosterone.  Pregnenolone is the only safe source of DHEA because your body converts it upon need.  Wild yam extracts (dioscorea) that claim to be a source of DHEA and progesterone are not because dioscorea cannot be converted to DHEA inside the body but only by manufacturing it synthetically.*