My son was given this several years ago to address his adhd and impulsiveness from Aspergers syndrome.
If I remember correctly I was to give him one per day, and it did seem to help calm him down it was a bit hard to estimate his intellectual functioning while taking it, but it did the job for which it was intended.

In the couple of years he was on it we had NO issues or side effects. the only reason we "went on" to another med was because in my boys case, he always seemed to get to the point where a med just couldn't do anymore.
Hope this helps...good luck