so let's get back to hair. what's the general consensus that high E is the best therapy? seems like that if high E is present it suppresses T anyway right? i would imagine the AA and 5ar woudln't be necessary but seems like most are on one or both. Is it more just to cover the bases and make sure? curious if anyone thinks progesterone is helpful.
a few (all we have, sadly) studies show that the response of hair follicles to E2 varies greatly from one region of the body to another (like DHT), and from one sex to another. In male's frontotemporal follicles, for example, it inhibits TGF-B2, which is the one of the main actors in Androgenetic Alopecia.
In the Hamilton studies it was shown that eunuchs that were administered with testosterone developed hairloss, but when ceasing administration, the hair didn't grow back. In contrast, there are amazing hair regrowth cases in the transgender community.
We don't know for sure (clinical studies) if and how much E2 is necessary for regrowth, although there is empirical evidence of one mtf averaging 90 pg/ml and regrowing hair.
AA's are not necessary when using enough e2, but "enough" may vary from one person to the other, and the suppression usually comes when your e2 levels are above 200 pg/ml.
Our goal is not transitioning, so we use lower doses of estradiol. Because of this, we also use anti-androgens (AA's).
Progesterone works as a anti-androgen, but there are much better options, like spironolactone, bicalutamide, etc. Not to be confused with progestins, which are synthetic, and not bio identical molecules used to mimic progesterone in female birth control. Many progestins have androgenic activity (unlike progesterone), so it's better to stay away from them.
As you can see, the general consensus is: it's complicated.
