I used it about two years ago for a year, IT did help.
I had to stop because I lost my Insurance. I am starting it again.
I just got the script fill today ad will start today..
As I remember , it takes a few weeks to feel any difference and
about 6 weeks before you will see an change in FEV1. That was
my experience when I used it before.
Good Luck, I hope it works as well for Your Son as it
did for me.