This is probably one of the least well understood topics by trans women I’ve seen, including me at the beginning. What we think is that taking female hormones is going to give us a feminine figure and boobs and that’s the reason to take them.
The truth is that hormones, unless you’re an adolescent who’s taken puberty blockers, are going to have modest effects and more modest in general the older you are. I actually did fairly well getting a modest B cup.
That said, breasts are less important in being seen as a woman than you might think, but they don’t hurt.
HRT does nothing to change your skeleton (again, unless you’re in puberty), so big bones are going to stay big.
But it turns out HRT does a bunch of other really useful things that are quite subtle and really do affect how you are perceived.
Skin changes – starting very early, in the first weeks even, skin starts to become softer and pores often become less noticeable.
Body hair – Aside from facial hair, other body hair will start to reduce to where after several years it may be very minimal.
Muscle mass – over a several year period you lose much of your “male” upper body strength. You too may need help opening jars!
Body odor – You won’t smell like a boy. I forget how long this takes to happen.
Brain changes – with estrogen on board and reduced testosterone you will likely be more emotionally sensitive and because of the reduced testosterone less aggressive.
Gonads – you have about six months to decide that HRT is a mistake before you risk permanent sterility (check with your endocrinologist!), it’s a good reason to continue thinking about how it’s going. You’re likely to stop ejaculating and over a longer period of time you may either stop having erections altogether or have smaller ones. On the plus side this helps with tucking.
If you go, or are going this route and you are at the end of a couple of years and frustrated that you don’t have an hourglass shape, remember that lots of natal women don’t either. I advise creative use of wardrobe.
On the plus side, if you’re thinking about transition but are thinking, oh, I have massive shoulders, go look at male and female skeletons and realize that once you’ve lost the excess muscle mass in your deltoids it won’t be so lopsided.
For those inevitable curious sorts, here is a progression of my face from well before transition to more or less now, the top left is from a number of years ago. The bottom left was just prior to starting HRT in Oct 2013. Middle top Dec 2013, bottom Apr 2014. Right is from Dec 2015 right after a hair appointment.
One thing you can’t see is the amount of hair regrowth. The bottom left and middle top photos are with wigs. The middle bottom and right are with hair pieces. The hair piece has narrowed significantly over the past two years. What isn’t clear is whether I’ll ever reach the point where I can get follicle transplants and dispense with the hair pieces. In the meantime they look good.