"works better than any other stimulant medicine i have tried. i have sensitivity to stimulants; it causes bruxism. the bruxism is absent with a 20 mg dose, and minimal with a 30 mg dose. other stimulants - i cannot take even the lowest dose without getting the bruxism side-effect to the point i can&#039;t stand it. also, i can&#039;t &quot;feel&quot; when it starts working and stops working - which is great. it wears off slowly starting about 7-8 hours after i take it. after 10-11 hours i do not feel it in my system anymore. no insomnia or &quot;crashing feeling&quot;. weight loss (ok since i am fat) about 25 lbs in 3 months. my only complaint is it makes me want to smoke. i quit smoking a long time ago. i think about wanting to have a cigarette several times a day."