You’re absolutely correct that a medication isn’t going to react the same for every person. People can have weird or even fatal reactions to medications. Any local pharmacist should be able to answer questions about medications and interactions.

To be clear, I am just saying that if adderall works for someone, vyvanse is likely to work for that person as well, because the drugs are so similar. Vyvanse’s biggest difference from adderall is that it’s a prodrug, meaning that starts off as a drug that has no effects on the body until it reacts with an natural enzyme we have in our colon which causes the drug to turn into what is basically adderall.

Adderall is mixed amphetamine salts.

The mixture is composed of equal parts racemic amphetamine and dextroamphetamine, which produces a ratio between dextroamphetamine and levoamphetamine, the two enantiomers of amphetamine.

Compared to vyvanse:

Lisdexamfetamine is an inactive prodrug that is converted in the body to dextroamphetamine, a pharmacologically active compound which is responsible for the drug's activity.

So technically, Adderall is dextroamphetamine and levoamphetamine. I can’t speak more to this because of my lack of knowledge but “dextro” and “levo” are “right” and “left”, basically meaning something like the left and right “versions” (wrong word) of the molecule. Vyvanse on the otherhand is just the right “version” (wrong word) of the molecule.