And I also found this file which is quite interesting. They say in their conclusion -

"estrogens plus antiandrogens in biological males block circulating androgens and sebum production almost completely, but inhibit hair growth only slowly. A strong reduction in hair-shaft diameter was the first sign of androgen deprivation, reaching its maximum after 4 months"

Its well worth a read, even if you only read the conclusion.

Download - Effects of Sex Steroid on TSs