It's all over where I live. If you take a tiny oral dose it's usually ok. Snorting it will DESTROY your nose though. Sub-lingual is fast but it tastes like shit and will give you sores.
It was made to replace Ritalin (about4x). There's white shit out there that's not pure and varies in potency. There is a legit source for the pure tan stuff.
It was never produced because it has a high dependency rate. I never had a problem. But if you chase it, you'll stay up days and then have the worst comedown ever. It's only going to be productive for cleaning, writing, something that doesn't involve focus. It's a pure stimulant, half and half with bars are popular here with the kandy kids.
It will be gone soon though, assholes are selling it as super=coke and drawing lines. Sending kids to the hospital and whatnot.