vyvanse

My son just started takeing vyvanse and i woul like to know how long does it take to get in to the system and show signs of working?

[Sandra Y, RPh]

Vyvanse reaches therapeutic levels in the body in approximately 3.5 hours.

[20101051]

i recently just started vyvanse and i feel like all of my effects are completely different from anyone else. i know everybody has a different reaction but mine seem very different. i take 40 mg at about 730 am. for periods 1-5 (until about noon) i feel focused and get a lot of work done (you say it takes about 3.5 hrs, but unless its all in my head, i feel the effects within about 45 min). then, it always seems that at 6th period (always the same time), no matter how hard i try, i can't get myself to focus. i become reserved, don't talk to anyone, and even other people notice i'm in a bad mood (opposite of the morning). is all of this in my head or is it possible that its due to the medication?