How do stimulants work??

Here's a basic depiction of the mechanism of action for both Adderall and Vyvanse. They're both stimulants, but are metabolized differently.

Adderall is made of amphetamine & dextroamphetamine. These go directly to the brain because it will recognize these molecules in a similar way that it recognizes dopamine neurotransmitters. The more you take, the more you feel the effects (which can be bad, so stick to your rx!)

Vyvanse is made of lisdexamfetamine, which is a pro-drug of dextroamphetamine. This means that the Vyvanse remains inactive until it's processed by the liver, which turns it into dextroamphetamine.

Since it's made by your body, you can't increase the effects of Vyvanse.

Think of Vyvanse as all of the ingredients your body needs to make cupcakes EXCEPT for flour. The flour comes from your liver and you only store so much in your cabinet.

You can take 3x the Vyvanse, but once your liver is out of flour, no more cupcakes (aka dextroamphetamine)

If you want to know more about ADHD stimulant medications, their effects, and their mechanisms of action, I made this rough video a while back. I plan on re-doing it at some point to make it more concise!