Armodafinil
Internet reviews about modafinil vary from 'cocaine like' to 'fucking useless'. Enough to spike my interest I suppose. I didn't want to dabble with getting prescription, so I ordered some from various sources. Fast forward 90 days I was sitting on yearly pill supply sent from India and Europe.
I started with half pill. Nope, not even placebo effect. Hour and half later I dropped another half and I got some effects. It's worth mentioning that the way modafinil works evolves rather quickly, tolerance builds up even quicker and you wont get the same effect you had when you took it for the first time.
Stimulation similiar to that of espresso, but good espresso with cup of water, not your shitty office one. And it lasts for quite a while, easily between 8 and 10 hours. Adding coffeine to it caused it to shift from making me nicely awake to 'where are my white gloves' speedy like.
As for brain performance, I wouldn't really count on that. You get CRAZY tunnel vision for first few times, but then it fades and it only keeps you awake. This is not very sustainable edge you can really exploit in a long run. It's useful yes, being able to be religiously concentrated on a book for two hours straight or force myself to work on a project. Or watch youtube videos. Yes, you start watching yt on modafinil you're pretty much fucked.
And it flushes your bowels, every single time. Doesn't nescessarily kills you aphetite, but food won't sit in your stomach, it wants out. Good, if you want to stay fit I suppose.
Mood goes into complete flatline. It's not euphoric and doesn't make you depressed. It's just massive meh, that keeps you awake. Nothing you could get addicted to. Especially knowing that tolerance goes up like crazy. After couple months of being on/off any speed effect is gone, tunnel vision is gone and all you have is staying awake. And if you're already tired to start with you will feel like shit. Awake shit to be extact.
If you were looking for something to make you Bradley Cooper like in Limitless, bad news: keep scrolling.