Vyvanse is a prodrug where lysine is cleaved from dextroamphetamine to release it over time.

“Vivance is a drug in which the pharmaceutical industry has taken one component of Adderall just the D amphetamine component and attached to it an amino acid called lysine now the amino acid lysine is a big amino acid and the attaching of Lysine to D amphetamine what we call vivance makes it what's called a pro drug it actually can't have any effect on its own but when one takes Vyvanse and it's broken down in the gut but to a greater extent actually in the bloodstream the lysines are cleaved off slowly over time and as a consequence Vyvanse is basically timed release dmphetamine”