Real name modafinil
Many poker players and medial job workers take it to stay focused, infact some poker players credit it to winning millions of dollars in a short period of time. There are no known side affects, and it's been on the market for years.
The movie LIMITLESS was based on provigil, basically an all encompassing focus drug with no drag or noticeability. Would be perfect for sitting on your ass for 8 hours and wrecking everyone at poker