Honestly, I feel like I can't really tell. If I told you you have to take X supplement or go do Y I would be lying.
I have taken a shit ton of different supplements, tried multiple oils and stuff like aloe vera, improved my diet, increased protein intake, taken high quality iron and so on.
These all play a factor probably.
Unfortunately I also took Finasteride for a short while(2 weeks) but stopped 1.5 years ago. This shit is poison.
Now if I run my hand through my hair I don't shed a single hair, just like before B5. After B5 when I rubbed my hair over my desk there would be 20+ strands of hair. Also when I wash my hair I don't notice any shedding.
I only ever noticed hair loss at the temples but I was shedding all over. Now it seems like the hair on my temples is thickening up again and very slowly my hairline is growing back in.
It could be due to a variety of reasons, I don't care very much about my hair anymore.
My only advice would be to avoid Finasteride like hell.
Read up on how they came up with the drug in the first place. https://tonic.vice.com/en_us/article/the-medical-mystery-behind-americas-best-selling-hair-loss-drug