Sorry, I don't understand this post. Can you repeat that somehow more obvious? I feel dumb xD sry
I don't think that statement was really correct. E2 can do everything that E2 plus an AA can do. It helps to know something about the history of MtF meds. People used to use ethinyl estradiol (synthetic) and Premarin (horse estrogens but natural) by themselves and if anything, gals had better results than now. Some think that the all but universal issue with lack of breast growth is because natural estrogens don't "work" as well as these two. Anecdotally, I was on Premarin for a couple of years and I have had outstanding breast growth.
So anyway, when it was discovered that these two were really rough on the liver, doctors began to switch to natural estradiol but there was a tendency, for liver safety, not to prescribe enough to reach adult female targets. This left MtF's not achieving full facial and hair restoration. As I say often, you have to maintain adult female targets for many months it seems to "turn on" hair growth for the majority of one's hair. It's confusing because you can see some marginal improvement at lower levels.
Hence, doctors started adding AA's to the mix since the gals weren't reaching targets on E2. Had more estrogen been used, however, the AA wouldn't have been necessary. That's one reason why testing can be important for those lacking the success that they want.
Now what about excessive feminization for guys on HRT from all of that estrogen? Here's the kicker. Your body feminizes in different areas at different rates and extensive hair growth/regrowth only comes at the end after you pass all but fully through the breast growth phase. So using less E2 to avoid feminization of breast tissue is likely to create more breast development, not less. This is because small amounts of E2 or even estrone or estriol, tricks the body into thinking, "oh, this is a girl ready for breast growth" so it turns on breast growth. Thought among MtF's is that people who titrate up from tiny amounts <raises hand> are likely to have more or much more breast growth than just starting at a level that reaches adult female targets.
When I started posting, I harped on this notion again and again because if you don't understand how female puberty works, you would think, "oh, I will just use less".
That's why I have reluctantly come to the conclusion that Serms are probably necessary to get both hair and avoid breast growth. However as I also reiterate, most MtF's have tiny breasts so this might be less of a concern. I am not the best spokeswoman here though because l followed the breast growth protocol unwittingly by using Premarin in tiny amounts (.30mg starting out!) and then doubled for titration every six months. I also used Estrogel on my breasts extensively and MtF's are uncertain whether topical application increases breast growth and many believe that it at least has some effect <raises hand>.
Some times there is a reason why people haven't done something in the past and we have known about estrogens since estradiol and estrone were isolated in the 1930's.