In my experience, being on T effected my sex drive, but not my sexuality.
Prior to T, I was both as far along the ace spectrum as you could be without being repulsed by sex and had absolutely zero libido. I never thought about sex, was never sexually attracted to anyone, I didn’t even know what to do with my sex parts because I’d never considered using them for anything except menstruating. Heck, I was so oblivious I didn’t realize other people thought about sex at all beyond, like, something you had to do if you wanted a kid, until I was in college!
And honestly I was very happy with that. I’d identified as asexual since I was 14 and learned the word, and it was really comforting to know I wasn’t the only one, and it wasn’t just the product of being raised female.
And when I started T I was concerned, like you are now, that all this momentum that I’d built up around my ace identity would be for nothing once I had some other hormones in me. If it turned out that my hormones were just screwy, what basis would I have for being asexual? Was asexuality even real? Would I lose that identity?
What I found was that while T gave me a small amount of sex drive, I was still not attracted to anyone. I was still very much asexual as an orientation, just with an ability to explore a part of myself I hadn’t before.
Discussion of masturbation/experience of sex drive below the cut-