Yes there are, and based on my personal experience with young FtMs, the changes can be very significant, however, it depends on your body. If you start before or during puberty ((About ages 11-16 for most genetic females)) There is a good chance your chest/ribs and shoulders (The actual bone)) may widen, whereas for an older transguy, the same may not happen, ((Your bones stop growing significantly sometime near the end of puberty.)) The voice changes can also be significant, usually if you start during puberty, it's easier for your body to adjust to having a deeper voice ((Since that's about the time it happens for a genetic male)) If you start around puberty, the only changes that will be different than if you start older will be in the bones and -possibly- voice. It depends on genetics and timing. This is not including the changes that could be prevented ((eg. breast growth, hip widening)) because these are only avoidable before puberty has started. I think after 18 the significant changes will basically be up to genetics, but that doesn't include bone growth. As for downstairs growth, that's all up to genetics. However, all other changes ((Muscle growth, fat redistribution, lower voice, hair growth)) will happen at any age. Ask your endo or doctor for more info, this is just from what my own doc has told me and mostly my experience with other young FtMs on T.
