I was obsessed with estriol for a while, thinking I could fix it to get my hairline back.
I can't tell you how much I used on the scalp because the product is topical and I used it in cream, I used too much cream on my head.
I used it for about 4 months before trying estradiol on the scalp too.
I did not see anything, without regrowth, perhaps the skin of the applied region improved a little, with no feminization effects at the time.
With 17 b I feminized but without regrowth in the hairline i stay for 100 days .
Estriol has a better affinity for the estrogen beta receptor (responsible for the anagen phase of hair)than estradiol 17b( affinity alfa=beta, but 17 is so much strong)
But estriol is weak, it doesn’t bind very well, physiologically it has a weak effect, I would say it’s not what it seems, but you can try, there are people who claim to have already managed with estriol, but it’s hard to believe.