It's been six years since my doctor diagnosed me as hypogonadic - Low testosterone.
Six months after I started HRT with testosterone, I was growing boobs and feeling very girly. All this was caused by the conversion of testosterone to estradiol by the agency of the enzyme aromatase.
Through this accident of biochemistry I discovered the wonders of estrogen. I began adding in Oestrogel and later injections of estradiol valerate. I then weaned myself off testosterone.
Last Spring I had my free testosterone checked and it was lower than normal for a 65 year old woman. Pretty close to zero.
I still take a testosterone shot every once in a while. Healthy people have a mix of estrogen and testosterone. It's only the relative ratio of hormones that make up male and female. I believe that transwomen who try to get to zero testosterone are misguided.
I would like to note that when my testosterone was very low and my estrogen in a normal female range, my dysphoria disappeared almost completely. I felt totally comfortable with my body and my place in society. For the first time in my life I was comfortable with who I was. I was just "me" and lacked discomfort with my sex or gender. I wasn't interested in crossdressing or reading blogs or forums about transsexuality.
I had, however, become somewhat lazy and indolent. I was sleeping more than I wanted to, and not exercising as much as I thought I should.
I added in some testosterone - just a little bit, and they dysphoria came back, even including a bit of (horrors!) ->-bleeped-<-. While I had been rather indifferent to my gender, the testosterone made me REALLY want to be girly.
I've posted this link before, but I'll post it here again. Psychologist Anne Vitale has written on the connection between dysphoria and testosterone. I think it's worth reading. It certainly rings true with me:
http://www.avitale.com/TNote15Testosterone.htmRandi