[toomuchtodo]

As someone who experiments with nootropics, I highly recommend modafinil over caffeine for sprints like that (up to 36 hours of wakefulness at a time, no jittery feeling, etc). You should not do it for any appreciable amount of time though. See https://reddit.com/r/nootropics for more info.

[pstuart]

Modafinil is much more expensive, harder to get, and not everybody responds to it.

[wahern]

I once watched three engineers take Modafinil for an all-nighter. It was their first time taking it.

By about midnight none of the engineers felt any different. One of them decided it wasn't doing anything and went to bed. The other two decided to keep hacking until they got tired.

Come morning the two guys who kept hacking were still hacking. The third guy said he slept soundly. The two guys who kept working said that, while the Modafinil never made them feel different, neither were they particularly sleepy. Exhausted, yes, but not sleepy.

The guy who decided to go to sleep used Modafinil after that and it worked as advertised. He just needed to realize that it wasn't going to make him feel stimulated.

I know that at least one paper shows efficacy dependent on certain alleles. But AFAIK none say that it doesn't work at all. And the majority of people have the alleles where Modafinil works well.

Compared with OD-ing on caffeine or other stimulants, I'd say Modafinil is the better choice. There's no substitute for sleep, and unlike normal stimulants you can usually deliberately go to sleep even after taking a full dose of Modafinl. Which means you can use your time more efficiently during a marathon and still get some proper rest.

[toomuchtodo]

Modafinil, while a bit more expensive than caffeine in pill form, is easily available online without a prescription.