5b-Pregnanediol (male)

5B-PD is the major progesterone metabolite. Increased levels may be due to high levels of progesterone and/or pregnenolone, progesterone supplementation, or adrenocorticohyperplasia. Elevations of both progesterone and pregnanediol have been reported in 21-hydroxylase deficiency.

Lower levels of pregnanediol may be due to decreased progesterone or 5-beta reductase activity.

The most important progesterone metabolite, pregnanediol (PDL), can serve as a urinary marker for endogenous progesterone levels and as an indicator of ovulation. PDL exists as two isomers, 5α-pregnanediol and 5β-pregnanediol. 5β-pregnanediol represents the majority end point of endogenous progesterone metabolism and appears to have little activity within the body, while 5α-pregnanediol, the lesser metabolite of PDL, can cross the blood brain barrier and may partially agonize GABA-A receptors.