The main role of progesterone in the male body is counterbalancing the effects of estrogen. What’s unknown to most men is that progesterone also serves as testosterone’s precursor.
This feature becomes much more important as men reach the age of 40 because this is the time when testosterone levels start declining and estrogen becomes more dominant.
However, when estrogen stays elevated, progesterone levels drop—and when this happens, testosterone levels will also fall even more.
Since low progesterone levels limit the availability of testosterone, symptoms like hair loss, low libido, fatigue, weight gain, and gynecomastia (or man boobs) may manifest.
Depression, bone loss, impotence, erectile dysfunction, and muscle loss may also occur. Men with low progesterone levels are at risk of developing serious conditions like prostatitis and prostate cancer.