... to 40 which seemed like a great dose. Then I decided to try 50. It seems like 40 was the best but since I had tried 50 for a while, but when I went back to 40 it didn't seem to work as well. Now that I have been on 5O for well over six months, I feel like it wears off too soon and I feel tired and not as focused. It is better when I take it than when I don't for sure. But it just is not helping like it used to. Should I increase the one dose or try taking one pill in the morning and one smaller dose later in the evening? Will I have to continue to do this as time goes on, or will one dose work if it is the right amount for the next several years? I originally started to take it for a binge eating, but it helps my attention deficit disorder greatly. The doctor has asked me if this dose this still OK, and would be willing to change it, but I told her that I thought it was OK, but I really don't. I wish I wasn't as tired as I am when I take it, but the tiredness eventually wanes, and I wish it lasted longer.