…to be more specific, the generic made by Barr prior to the transfer of rights for the name brand was probably even worse than it is today. After the sale (around 2013?) it seemed to improve dramatically. I know this because I switched back and forth (between generic and NB) a number of times and because, following the sale, the name brand was made by the same company that also seems to distribute to just about every pharmacy in the area — meaning: whenever I switched between name brand and generic, it was always to a Teva/Barr product.
And yes, regardless of what “they” claim, there is a big difference between name brand and generic. If I had to guess, based on my reaction to the Teva/Barr generic I’m taking now (9/1/2021), the generic barely seems to have any dextro-amphetamine effect: a) I mostly just feel peripheral nervous system effects (“weird” feelings in my body) and b) it does nearly nothing anymore to keep me awake. There was never a single instance while taking the name brand that I ever experienced anything like this — and I have taken both generic and name brand, at different times, for several years each (at least 3-4 years each without interruption). I am certainly not “imagining” that I can barely stay awake with these generics. It’s gotten to the point where even I have to weigh whether the side effects are worth it, since all there is anymo0re is side effects.