Quoted By:
From what I've ready, the effects of hormone therapy vary drastically depending on age. An individual born male who is given high amounts of estrogen before puberty will end up looking much more feminine as the bone structure and density will more closely match that of a female body as well as hair growth patterns. The individual has a greater chance of growing larger breasts at that point as well... though I question how responsible it is to give a child who hasn't even reached puberty hormone therapy, unless the doctor cut off it's penis during a botched circumcision or something.
After puberty, a lot of things won't change. Hair grown pattern vary a lot less dramatically and bone structure will not change. The older the individual gets, the less dramatic the changes, to a point where there may be little to no change in physical structure after a certain age.
There are certain masculine and femine physical traits that develop before puberty, so hormone therapy will rarely make an individual born male look 100% female.
Apparently, the hormones often cause impotence and, if given before puberty, will have a greater chance of causing conditions such as micropenis, where the penis is less than 2 inches long fully erect, if it can even become erect.