its spelled Vyvanse. Its Lisdexamphetamine, which is amphetamine coupled with lysine. Its metabolised slowly and activates slowly, which might make it less effective for getting high. Wikipedia says "150 mg Vyvanse produced a "likeability"—euphoric effect—that was determined to be indistinguishable from 200 mg of the Schedule IV drug diethylpropion hydrochloride or 40 mg of dextroamphetamine."
I'm prescribed to 30mg of Vyvanse a day and I used to take it a lot because of the high it gave, but I stopped because I was becoming an asshole when I would come down from it. Wikipedia does say that 150mg is the "likeability" threshold, but I weigh 145 lbs and 30mg still gets me twacked as hell. It's very similar to Adderall XR, but the high/tweak is a lot more smooth. Less ups and downs.
