I've used it as a Now brand cream at 20mg per day. First thing, it makes you feel really calm. I have noted more vascularity. Estrogen tends to make me flush and the cream stopped that flushing and seemed to improve the texture and elasticity of my skin. Looking at a steroid pathway chart, progesterone has a number of options of conversion beyond it's one direct cellular effects. So, I think it would be difficult for anyone to make a pan statement on it's effects without knowing details of the plasma or saliva levels of many other endogenous hormones at the same time.
There are a number of websites clearly advocating progesterone cream , some at up to 100mg a day for males which does seem rather excessive. They do site studies to support their claims, but I imagine there are other studies out there conflicting with their assertions.
I have found that a little progesterone cream with some testosterone gel makes me feel great. Interestingly, all my various trt attempts in various forms and doses did not boost libido, but the low dose combo with progesterone definitely did.
Is some converting to testosterone or androstenedione? It's possible. Several studies clearly point to progesterone being THE hormone of libido, not testosterone, though clearly they require suitable levels of each other for optimum function.
The brilliant endo and biologist Ray Peat advocates progesterone only treatment for men over sixty and he has published an extensive body of work on it's life extending, anti inflammatory powers. He also tested it on himself at supraphysiological doses without sides and it certainly didn't shut him down. Personally, well under the 60 bracket, I think it's something one has to try small amounts of and gauge their own responses. As for blood tests - that would be great if everybody had a blood profile on their 18th birthday, then they would know what to aim for. I'm convinced that many guys out there probably have odd combinations of hormones at 18, which due to genetics, work for them. I wish I had profiled at that age - but it's the very last thing you think about then!
Many athletes and physicians advocate pregnenolone for men, rather than progesterone. The thing is, nobody knows what way preg will go once it's in the system... Cortisol? Aldosterone? Testosterone? Progesterone is a step along the chain and it may all stay in that form effecting what prog is supposed to - like inflammation and regenerative functions. I do know it is pro thyroid and anything that supports thyroid is a big issue because even a mild hypo condition can set up a cascade of degenerative failures.
Anyway, these are my opinions and experiences and I hope they contribute to the debate
