Sleep deprivation's negative impact on testosterone and estrogen may be largely due to excessive light exposure during the night.

“viewing bright light with the eyes in the middle of the circadian night has a detrimental effect on dopamine, and therefore has a detrimental effect on things like testosterone and estrogen”

“I would wager that a major effect of sleep deprivation on reducing testosterone and estrogen is not necessarily because of the lack of sleep per se, it's because usually when people are not getting enough sleep, they're getting too much light in their eyes in the middle of the night as well”

“what we know is that a night of total deprivation will markedly imper those hormones”

“they will have a level of testosterone which is similar to someone who is probably 10 years older than them”

“middle of the night you are suppressing dopamine release if you're suppressing dopamine release you are suppressing pressing testosterone levels”