In some situations, the brain is performance-limited by the available fuel. Increase the fuel and you can temporarily get a performance boost.
The smart drug page definitely needs work. This page should be merged with it though. If your writing about fuel alone, the only thing you can say is drink glucose. Of course, amino acids and neccesarry constituents of neurotransmitters could be called "fuel," but their not, simply because they provide signalling and building blocks, not energy.
Freeform discussion of this hack goes here.
Errata go here. Errata go here. Errata go here.
This is a page for a hack from the book MindPerformanceHacks by Ron Hale-Evans.