Zak: Depending on your age, estrogen blockers might be prescribed before testosterone. If you physically transition earlier in the puberty process, though, you can potentially avoid the need for top surgery by suppressing estrogen before breast development begins. There also may be a potential for growing taller if physical transition is undertaken before estrogen fuses the growth plates. All of this stuff that you could stand to benefit from, though, occurs in the earlier stages of puberty. I’m not a doctor or an expert on this AT ALL, but I would say that the difference between transitioning at 15-17 (mid to late teens) versus 18+ would be negligible, whereas the difference between transitioning at 11-13 (pre or early teens) and 18+ would be more significant. A lot of this would have to do with avoiding an estrogen-driven puberty, not necessarily when testosterone was started. At least this is my understanding (please correct me if I’m wrong!).
A lot of the cons of starting testosterone earlier center on the more social/emotional issues involved, but the vast majority of these would depend on the individual involved and their situation.

