Well I bought some for my niece and she is 11. Her hair was breaking badly in the back, she has already had a relaxer (but she gets them infrequently), so whatever products I think will help her hair that has becomce damaged, especially if I have received good results with them, I get for her.
The hair product would be the last thing I worry about when it comes to hormones for my niece, I could see if I was giving her protein shakes or the vitamins I take or something, but my niece (mainly due to heredity) is a big girl, I mean she is tall and solid. When my ex-boyfriend was in college studying Civil Engineering, he was taking classes on water treatment and he told me then, that there are tons of hormones in water that have these kids growing and acting ridiculously. I know that there is a lot of hormones in food too, so I probably wouldn't be that concerned with the hair products I put in the child's head as much as I would what they take orally the products that they intake on a daily basis, water and food. I am just saying I don't think it is anything wrong with using very small amounts on your child's hair, and maybe the recommended usage for damaged hair.