I did stupid things too when I was young, I started hairloss at 17 ! and hair was all for me, I used oral spironolactone, topical flutamide, oral minoxidil, etc, etc, etc. Dangerous things. WE are talking about but in the lates 90s, there was not tons of information as you can get now.
In fact, the new hype or oral minoxidil is just a big LOL, do a search on hairsite, regrowth sites, etc. It was extremly popular back in early 2000s as it was oral spironolactone. Of course , tons of side effects, not better results than topical, etc. It is all there, google it ! . And now, almost 20 years later, a couple of stupid doctors say that is the best thing you can try, lol.
So, rewind it. You don't need to chemical castrate it to stop hair loss. Even if you do, in most cases, you will not a get a full regrowth. And , if you do, short and long side effects, don't worth it . Use oral antiandrogen, and if you do topical most of them will go systemic, so it is the same, will give you tons of side effects, some of them will be irreversibles . We are talkign about penis, testicles, BONES !!!!!!! even the f*****g brain for the ones that pass blood brain barrier and/or the zones of the brain that are not cover from this barrier ( like the hypophysis ) .