"i was prescribed this by my doctor and it was terrible. i stopped taking it after 5 days because my doctor told me to. it made me angry all the time. it did not help my concentration. also, 3 days after taking it i still have shortness of breathe, my heart is still beating hard, and the left part of my chest has immense pressure on it. i&#039;m never taking this stuff again. trust me, nobody needs it."