Causes of transsexuality Docter and others, but opposed by Charles Allen Moser, Larry Nuttbrock, Julia Serano, and the World Professional Association for Transgender Health.<section end="factors" /> A 2008 study compared 112 male-to-female transsexuals (both androphilic and gynephilic), mostly already undergoing hormone treatment, with 258 cisgender male controls. Male-to-female transsexuals were more likely than cisgender males to have a longer version of a receptor gene (longer repetitions of the gene) for the sex hormone androgen or testosterone, which reduced its effectiveness at binding testosterone. The androgen receptor (NR3C4) is activated by the binding of testosterone or dihydrotestosterone, where it plays a critical role in
Transgender hormone therapy (male-to-female) produce full progestogenic effects with oral administration. Some progestins, such as medroxyprogesterone acetate and hydroxyprogesterone caproate, are or can be used by intramuscular or subcutaneous injection instead. Almost all progestins, with the exception of dydrogesterone, have antigonadotropic effects. The main effects of hormone therapy in transgender women are feminization and demasculinization, and are as follows: Breast, nipple, and areolar development varies considerably depending on genetics, body composition, age of HRT initiation, and many other factors. Development can take a couple years to nearly a decade for some. However, many transgender women report there is often a "stall" in breast growth