What are the adverse side effects of NO2 (arginine alpha ketoglutarate) ?

Being so new, it doesn't have much of a track record to go on so far, but the general consensus right now is that
1. High doses of arginine may be toxic,
2. Overuse can lead to diarrhea and nausea.
For more, check these links (but beware of websites who sell the product; you can imagine they might only say good things about it).