"i recently was diagnosed with adhd and was started on 20 mg. the first day  i took it i felt great! i was energized and motivated. i did have trouble sleeping but that ended after the first week. i will warn you about the side effects because those hit me pretty hard. i had headaches daily, fast heart rate, dizziness, and blurry vision. that lasted about 2 weeks and eventually passed although i still had the fast heart rate. it decreased my appetite because i was no longer snacking and was getting full a lot faster. after about 3 weeks i noticed that the &quot;good feeling&quot; was gone and i felt a crash throughout the day like i had no energy.  my doctor just prescribed me 30mg and i&#039;m on day 3."