How do you know when your hair has stabilized

[Awjones]

I'm 20 years old, 21 in 3 months and noticed my hair loss just as I was turning 18. So for hair transplants they always say wait until your hair stabalizes. Now I know Im too young now, but I was wondering how can you tell when your hair loss has stabalized?
Using minox and saw palmetto for about 8 months now.
Current hair state pulled back and in harshest lighting I have. Any recommendations on slowing the loss and/or making a fuller appearance?