Prenatal hormones and sexual orientation Only 23% of childhood gender problems will result in transsexuality in adulthood. Drawing on some transsexualism cases, Garcia-Falgueras and Swaab state that "[f]rom these examples it appears that the direct action of testosterone on the developing brain in boys and the lack of such action on the developing brain in girls are crucial factors in the development of male and female gender identity and sexual orientation ... ." Countless studies have been run on peripheral levels of sex steroids in male and female homosexuals, a considerable number of which claimed to find "less 'male hormone' and/or more 'female hormone' in
Transgender hormone therapy (male-to-female) arousal would be inhibited; alternatively, if high doses of estrogen negatively impact sexual desire, which has been found in some research with cisgender women, it is hypothesized that combining androgens with high levels of estrogen would intensify this outcome. Unfortunately, to date there haven’t been any randomized clinical trials looking at the relationship between type and dose of transgender hormone therapy, so the relationship between them remains unclear. Typically, the estrogens given for male-to-female gender transition are 2 to 3 times higher than the recommended dose for HRT in postmenopausal women. Pharmacokinetic studies indicate taking these increased doses may lead