In the more distant past I was told that high cortisol robbed precursors from testosterone (pregnanolone?). Then more recently I’ve read articles that cortisol can’t literally take raw materials that would have gone to testosterone. Now, I’m currently seeing infomercials claiming that while cortisol doesn’t directly rob materials upstream from testosterone, that high cortisol a) signals the body to make less testosterone (possibly) and b) definitely reduces testosterone sensitivity. I’ve also seen some research that resistance training may lead to a medium term reduction in testosterone, but that it is not a problem since it raises testosterone sensitivity. Is it possible to get a clear explanation of these processes, which are legit and which are not?
On a side note, I tried melatonin for a stretch of time late in the day on training days to reduce cortisol levels. My testosterone blood levels rose over a six week period and that is after hanging around 500 total T, 70 free for a while. It had actually been lower when I was overusing caffeine, but I cut PM caffeine and it went from 250/40 to 500/70 over about 10-14 weeks. On the melatonin, it went to 670 after 6 weeks. The problem is that if I drop melatonin now, I start to have increased anxiety that takes about a week to get over, so I don’t know if it’s a good idea in the long term.