I drink energy drinks or caffeinated soda.. that seems to be less harsh and more natural in comparison of he stimulant meds.
but as a kid, it didn't have a good reaction to any of it. (mainly because i am autistic. but since there was no option for me to have it (in my parents eyes), the next closest thing the pdoc could come up with was adhd.) the stimulants help a lot more (Actually i can't function as independantly as i do now, without them...sadly...) as an adult.

But some other therapy's could be horse therapy, or maybe even tho he doesn't have autism, some of the skills and things learned in ABA or other autism therapy's could be of some benefit to him.
depending on what he struggles with most, there may be specific computer games geared towards those struggles. Or if he has a ipad or iphone, there are some pretty useful apps on them. I dont know of any that is address ADHD as a whole. but there are a lot of skill building apps and helpful schedules and such that could be helpful?