The post above me is incorrect. Vyvanse's chemical name is lisdexamphetamine, the formulation is not all that dissimilar to Adderall XR. Adderall is roughly made up of 75% d-amphetamine, the other quarter being the isolated left side of the molecule l-amphetamine. Lisdexamphetamine is d-amphetamine coupled with L-lysine. The significance of this is that the extended release mechanism in Vyvanse does not rely soley in the pill itself but the molecule. The formulation has to be hydrolyzed in the intestine by a special protein before the d-amphetamine is released from the molecule, obviously, this now makes it much harder for abusers to get a high from injecting/snorting - doing this will actually give the person less effects than if it was taken orally. As you can see, it doesnt matter if you sprinkle the powder in a drink, the release lies in the molecule itself. So you have nothing to worry about by breaking the pill open. As for the "premed student", I am still in highschool and aquired this information easily off the net, I suggest you do the same before posting.