Why does Vyvanse give you such as shit feeling the whole time, then worse at the crash, while Adderall (I have no experience with pure dextroamphetamine) is perfectly normal feeling, as in speedy euphoria and what not. I know about the pharmacokinetics of lisdexamfetamine dimesylate, so no need to mention the initial GI metabolism. I'm just wondering why no matter what, Vyvanse is just shit.