I’m currently switching to Vyvanse after 10+ years using adderall. There is no generic formulation (at least in the us) because it came to market in 2007. I’ve had several issues with inconsistent adderall from various generic manufacturers and that issue simply isn’t possible right now with Vyvanse. The downside is, it’s $400 a month without insurance, and $100 a month with good insurance.

Because it’s basically dextroamphetamine with a lysine molecule taped on, the psychoactive effects are really similar, but I’d describe it as cleaner if that makes sense. The “killer feature” of the enzymatic release is it’s basically a fixed timing, whereas with XR formulations of Adderall you have a 50/50 blend of immediate and delayed release 3:1 amphetamines. I believe you are correct, it’s not standardized. This, combined with the acids / bases both hurting overall blood levels (think grapefruit juice) means you just have a wildly inconsistent time over long term use of the medicine. For example, I’ve had pharmacies change generics on me without saying anything, I’ve had an inability to get my preferred generics, and I’ve had days where it’s felt like I took nothing at all. The worst are Nuvo and Mallinckrodt in my experience (IR 10mg 2x/day).

I’ve only been using Vyvanse for a week or so, but I can say it’s a marked improvement for me and the lack of a generic is a huge boon with regards to consistency.