I honestly think that levels of estrogen in HRT will vary from person to person, because everyone's body is different. I'm also on a form of birth control myself, a combined pill which has a high dosage of estrogen and a small amount of progesterone too. I've been taking it for 4 months and although I don't see too many changes myself, others do. My breasts developed fairly normally, very quickly, and are now just shy of an A cup. My skin tone and scent changed dramatically and my figure altered slowly going in different directions for a few weeks until calming down to give me a sporty female figure. Then again I was incredibly slim when I started, my T level was miniscule because I suffered a sporting injury in hockey which damaged my testes when I was 17 and my body fat was quite low. Taking the pill made me put on weight despite no change in my dietary intake, and lose my masculine muscle mass very quickly. In fact I lost my core muscle strength within the first 2 weeks and had to ask for help getting off the sofa, it was that dramatic.
Can I just say to discourage people considering using the pill as a form of HRT, that my results are not to be generalised and different people will react differently to the synthetic estrogen they contain. As my T level was so remarkably low in the first place, the tiny amount of estrogen in the pill I take, was able to override the power of the T in my system very quickly, but the average (and I am not average) male bodied person transitioning will need much higher levels of estrogen and perhaps a T blocker to combat the T in their system. We are all different. The best advice I can give anyone is to only use HRT under the supervision of medical professionals as you can damage yourself if you are not careful.
