I guess for me it really depends on how I look at it, my reaction after the first week was enough for me to know I Never wanted to go back or be Off Estrogen. Physically and I`m already past that point of no return now, i can`t actually say there was a specific moment as such.
Trans men transition all the time, so with that in mind, is there actually any point of no return?
I can never become a man because I`v never actually been one and no surgery or HRT can alter your Gender, for me to re-resemble one again would require surgery, acting lessons, a wig (or hair dye and cut), substanial amounts of alcohol and good deal of bribe money! LOL
but even then it could only be as a temporary act, because my real name would still be Katherine and all my legal docs are in my name too, so I couldn`t Live as one.
so take your pick, at what point was it No return?