I already had slight gynecomastia and very weird hormone levels before starting Spiro recently, and my doctor thinks I might have some mild intersex condition.
I noticed changes after less than two weeks, and the initial reaction was simply an "oh, it's starting already", followed by jumping with excitement, then some combined fear and relief, since it's finally getting serious, meaning I will have to come out to the "public" within a year or so (only close friends, a few random acquaintances and immediate family know as of now). But then that's also what I've been waiting for, even if it's scary!
After a few days, the itching started, then soreness. I jumped with excitement at that too, followed by the realization that I was supposed to go to a martial arts seminar a few hours later, and that a weekend of being tossed around would probably hurt a lot, combined with the less than soft fabric of my t-shirts and keikogi. A bit later, I found myself in a clothing store paying for a sports bra with a tortured look on my face, and then in the male wardrobe (I truly hate still having to use it) putting it on. The culture I live in emphasises politeness and watching one's own business, so I didn't receive any comments, but I sure did get some sideways glances... The bra worked at least, I survived the weekend. My recently-lowered blood pressure and the diuretic effects of Spiro were a bigger problem.
To sum up, I loved and love it, even the painful parts. I actually found the seminar part a bit entertaining (and the female friends of mine who I told couldn't stop laughing), despite the part about the male wardrobe being humiliating. But I guess that's something everyone has to go through, at least if they use gyms, dojos or anything similar without private or gender neutral wardrobes. The only thing that annoys me now is that I can't stop touching them, and that kind of makes the itching and soreness worse.