I switched from Concerta 36mg to Vyvanse 50mg on the request of my doctor, since Concerta, after years on it started giving me paradoxical reactions, like putting me to sleep like a ton of bricks.

At first I was considering 50mg as being too much to handle, and lowered to it 25mg than adjusted myself around 30mg. That was Vyvanse brand name, and I had enough of it to last me 60 days or so.

Recently I had to refil, so I went for the cheaper generics, picked one of them and found out that 30mg wasn't doing it anymore, so upped to 50mg and was able to feel it working again. Is that a common/noticeable issue?

Edit: I don't really spend a second thinking about generics quality and so on. Everything else I take is generic when it's cheaper, and it has always been like that. I believe I carry no bias on this.