Since progesterone is a potent inhibitor of 5-alpha reductase, decreasing in older men progesterone plays a role in increasing the rate of conversion of testosterone to DHT.Mesolimbo wrote: generally reduce sexual desire in males. This fact lead to progestins being used in chemical castration of male sex offenders.
The mechanism by which progesterone and progestins reduce male libido is not fully explained by their ability to reduce plasma testosterone, as normal testosterone level can be found in both impotent and hypersexual males
Although.
important for male fertility It's because it acts on spermatogenesis, testosterone production synthesized by Leydig cells and facilitating training and sperm motility.
About pfs:
Plasma DHT and statistically significant decreased levels allopregnanolone, and high levels of pregnenolone were observed (the latter two are neurosteroids) and so does DHEA.
https://www.andrologica.es/la-progesterona-hombre/#
Change language in the upper left corner to english
We conclude that progesterone and the 19-nor-derivatives inhibit 5 alpha-reductase activity at high doses.
https://www.ncbi.nlm.nih.gov/m/pubmed/1828548/
Some memebers here have high progesterone i think.
And i find i bit odd that is suggesting progesterone works as a 5-alpha redutaced inhibitor by himself.
Sorry if I'm wrong, im just try to help