"i&#039;m 24, in gradschool and i&#039;ve been taking the 70mg for about four months.  at first i lost ten pounds but now have maintained my appetite.  when i don&#039;t take it i do feel an uncontrollable desire to eat a lot.  i have difficulty sleeping at night and sometimes won&#039;t fall asleep until 3 or 4 am, and i take the medicine as soon as i wake up. i think it works best a few hours after taking it. feel no anxiety and accomplish a lot- but then wears off by the afternoon.  also i was prescribed an anti-depressant before but i feel this somewhat takes care of that. i still prefer taking vyvanse now but i do think i&#039;ll stop for a while after graduating because i&#039;m not sure about the long term effects."