Both drugs are psychostimulants used by psychiatrists to manage ADHD. Amphetamine is the active agent in Vyvanse and Adderall. The main difference, chemically speaking, is that Vyvanse is metabolized to d-amphetamine, but Adderall contains a mixture of d-amphetamine and l-amphetamine.
Relative Potency of Vyvanse vs Adderall
Adderall is more potent than Vyvanse. What this means is, if you took an equal dose (in milligrams) of Adderall and compared it to Vyvanse, Adderall would have more pronounced effects.
There are a couple of reasons for Adderall’s increased potency. First, it’s instant-release. It is quickly absorbed in the gastrointestinal tract and enters the blood stream.
Vyvanse (lisdexamfetamine) is a produg for d-amphetamine. Only some of ingested lisdexamfetamine is converted to d-amphetamine.
But although lisdexamfetamine is less immediately potent, it is longer lasting. Vyvanse lasts about twice as long as Adderall. So overall, a similar dose of amphetamine is delivered, but at a slower rate.
How Much More Potent Is Adderall?
A 30mg dose of Vyvanse is equivalent in potency to 16.2mg of Adderall. However, the 30mg of Vyvanse is released over a longer time frame. So, a 16.2mg dose of Adderall is delivered over 6 hours vs 30mg of Vyvanse which is delivered over 12 hours. Learn more about how to inter-convert Adderall and Vyvanse dosages.