The only real fix for hair loss is a transplant. If RU58841 or any other drug really, seriously, worked as claimed, it would be sold behind the counter at pharmacies for huge prices. Hair loss comes down to:
Genetics/Age (When did your father begin losing his hair if at all?)
Hair care routines (Seriously just treat your hair like women do for best results)
Diet (We're the product of what we put into ourselves after all)
I had mid back length hair in high school/teenage years and kept it until my late 20s with no issues despite starting gear at 25, and only cut it short because I stopped wanting to be an emo/rocker looking guy. If I let it go for a few months it'll be down past my shoulders again and my hairline is fine, as is the crown area.
I would say the biggest threat to your hair is not so much the anabolics but rather the AI/SERM products out there as hair quality, length and fullness seems quite correlated with higher estrogen levels as we can clearly see women have much more, longer, healthier hair than men in general. Now, not all cases are the same but certainly it has some influence on hair growth and health for sure. I personally hardly ever use(d) AIs as I rarely noticed any kind of side effects that could be handled through those drugs, which might have played a role in how healthy my hair is/was. Consider cutting back your AI usage perhaps, as the most commonly followed 'protocol' is for people to pop 12.5mg/day Asin or .5mg/day Adex and that is absolutely overkill and unnecessary for the majority of people running gear.