Definitely, many people try treating ADHD without medicines. It's important to stick with the behavioral treatments, though.
And at some later time, you (or he) might decide to try the meds again. Maybe later in his education he'll find that he needs the medicine to help him, and maybe he'll find a drug that works without those awful side effects.
Myself, I took medicine for two years, and it helped me a lot, but now I do reasonably well without it.