Also consider modafinil
there are plenty of other common stimulants, but caffeine is by far the most commonly used — and also the most likely to be taken mixed into a tasty drink, rather than in a pill.
Also consider modafinil
there are plenty of other common stimulants, but caffeine is by far the most commonly used — and also the most likely to be taken mixed into a tasty drink, rather than in a pill.