Vit B6 helps some, but be careful about the source (could contain gluten)
If you're using omega 3's that contain Evening Primrose oil that's been indicated as problematic sometimes too, I think.
Tesco's one a day omega 3's work well for my son, but are bigger than 'that brand'
ben has the 'push me pull you' AS/ADHD combo too and i've never medicated as trials always proved problematic - i.e. a dose that helped ADHD affected his concentration/functioning so much that the trade off wasn't worthwhile... GF/DF made some big advances, but there were other indicators to point me towards this too... He still seems to 'swings and roundabouts' periods where ADHD is more problematic, and they've occassionally been bad enough to hedge me toward medication again, but always with the same 'trade off' results.
Much better generally than he used to be, and I'm anticipating that adolescence will bring more problems, but eventually lead to a more stable adulthood, which seems to be quite common whether ADHD alone or the double whammy!
I would also consider very carefully just how exclusive 'hyper at home' is... If he's demonstrating problematic behaviours only
at home then you need to think about that, and not just in an 'oh it's the only place he feels comnfortable enough to let it out' or 'it's the release after all the effort at school' sort of way. They are very common responses to situations that have a far less complicated explanation...
Hope that helps