So, I'll be using words regarding what the title is about, and words about the internal organs involved in this monthly nightmare, so if that bothers you, don't read on.
OK, so it never occurred to me before, but I just wondered. Once you start testosterone and you stop having periods, what happens with the lining of your uterus? Does it carry on building up and not shedding or does it stop, you know, rebuilding? Is it not dangerous to stop?
It stops lining. I had one of those echo things to see if everything was well after a couple of months on T. The doc informed me that the uterus' walls were 'nice and thin'. So nothing had build up in those months.
The estrogen is what triggers the endometrial cells (the cells in the uterus that collect blood and engorge to create the lining) to do their work. Without the estrogen, the cells stay dormant so no lining is built, thus there is nothing to shed.
(Side note: This is why T is such a gift to those of us with endometriosis!)