My DD11 has been on it for 2 years now and it has been a godsend. We do 5mg a night which her sleep doctor is okay with, but we also do Iron for her restless leg syndrome. She grew about 8 inches in 4 months after starting the Melatonin and iron. She leveled off for awhile and now is growing again. She is around 5 feet tall right now and growing.
If she doesn't take the melatonin she is up till midnight or later but the nights she takes it she is asleep within a half hour.

Cassie

"Imperfections in our journey were what made it perfect."-Ewan McGregor