Definitely check out
Ephedrine (it's in over-the-counter
Bronkaid).
Wikipedia says it's "commonly used as a stimulant, appetite suppressant, concentration aid, decongestant, and to treat hypotension associated with anesthesia". But it's a bit rough on your heart, so be careful with that. And from what I've read, you develop a tolerance fairly quickly.
You should look into Propylhexedrine, which is in over-the-counter Benzedrex inhalers. This involves breaking open the inhaler and eating the cotton inside which everyone says tastes terrible. From what I've read, it's similar to some ADHD medication, and there are methods to extract the
propylhexedrine so you don't have to eat the lavender-menthol cotton.
Finally, check out
Modafinil (
Provigil), both are restricted in the US but I believe
Adrafinil is unregulated, and Wikipedia says that Adrafinil is "metabolized in vivo to
Modafinil", which has actually been considered for an ADHD medication.
Good luck!