Next year I have to do a study as a school project. I will probably have access to about 10-20 test subjects, maybe more if I beg, and a lab with a full battery of professional-level cognitive tests. I'd like to study nootropic drugs and see how well they work, but the only one I'm really familiar with, piracetam, is by prescription only in Ireland, and I'm not likely to be able to prescribe it for this study.

So, nootropics experts, can you think of a drug or supplement that needs testing, that you think will return measurable results in a study of only 10-20 people, that works quickly (ie no "have to take this for a month before seeing effects", preferably <2 hr onset of action) and which is sold over-the-counter in Europe?