There are two types of stimulants: amphetamine (Adderall, Vyvanse, Evekeo…) and methylphenidate (Ritalin, Concerta, Quillivant…). Almost everyone does well on one type or the other, but not both. So Vyvanse is a different type of stimulant altogether.
You can read about this and more information you need to help your son find the right medication and dosage here: https://www.additudemag.com/stimulant-medications-for-adhd/
ADDitude Community Moderator, Parenting ADHD Trainer & Author, Mom to teen w/ ADHD, LDs, and autism