Adderall (amphetamine and dextroamphetamine) and Vyvanse (lisdexamfetamine) are very similar. Both are central nervous system stimulants approved to treat ADHD. Adderall can be obtained in a generic version that’s relatively inexpensive, but Vyvanse is only available as brand-name.
Both drugs are classified as Schedule II controlled substances by the Drug Enforcement Administration (DEA) and can only be obtained with a prescription from a physician. The federal government considers both of these drugs to have a significant potential for physical dependence in people who use them and are high-risk potential drugs of abuse.
Adderall comes in an immediate-release form and an extended-release form, while Vyvanse only comes in extended-release. The duration of action for the immediate-release version of Adderall is about 4–6 hours, while the extended-release version lasts about 12 hours. The duration of effects for Vyvanse is about 10–13 hours, though some studies report it is up to 14 hours.
The main difference between the two medications is that Vyvanse is a prodrug, which is a substance that is inactive in the system until enzymes in the body metabolize it and convert it into the active medication. Vyvanse can only be taken orally, whereas Adderall can be ground up and snorted or mixed with water and injected. It also means that the side effects from Vyvanse are considered to be less harsh than with Adderall, and Vyvanse has a lower risk of abuse. In addition, prodrugs like Vyvanse are believed to be absorbed much more efficiently and smoothly due to their biochemistry. When the drug wears off, it is believed to produce fewer negative effects.