"i have to give vyvanse a solid 10. i asked my dr to switch me from adderall instant release 20mg 2x a day to vyvanse and in my honest opinion this was the best decision i made. vyvanse helps me focus, more motivation, feels more subtle which i absolutely love. adderall for some reason made me feel like a different person, but with vyvanse i feel like myself still which is great. it is really long lasting, i don&#039;t know or understand how people say it only last for a few hours when in my experience it last a good 12-13 hrs. in fact i heard people say it loses potency after 4 hours or so but in my experience i think it actually increases. but this is just my experience, and maybe metabolism aswell but anyway i hope this is helpful for others."