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Pregnenolone

Pregnenolone is a naturally occurring steroid and is an intermediate in the biosynthesis of progesterone and corticosteroids. It has no known hormonal activity of its own, however. Pregnenolone is a steroid precursor produced in the human adrenal gland and in the human brain. Pregnenolone is produced in the desired amounts only if a person's body has adequate amounts of cholesterol, vitamin A, thyroid hormone, and enzymes. If these levels are insufficient, a low supply of pregnenolone will result. Pregnenolone is a precursor for dehydroepiandrosterone. Dehydroepiandrosterone (DHEA) is a precursor of androstenedione. Androstenedione is a direct precursor of estrone and testosterone in target tissues that possess the appropriate receptors and enzymes. Pregnenolone levels are similar in both males and females. In a healthy person, the conversion of cholesterol to pregnenolone occurs inside the mitochondria. Once produced, pregnenolone leaves the mitochondria and does not inhibit its own synthesis. Of all steroidal hormones, pregnenolone has the greatest memory-enhancing effect, and can improve post-learning memory function at a dose 100 times lower than other memory-promoting steroids.

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