Then why are some people so much smarter than others?
We know that the variation in any single locus is responsible for < 1/100 of the variance of IQ. If genes corresponded to drugs, then that gives an upper bound on the efficacy of drugs. I think that we can agree that 100 does not counts as "a few."
So Scott Alexander's post at http://slatestarcodex.com/2016/03/01/2016-nootropics-survey-results/ shows that the most "effective" "nootropics" have still been the ones that have existed for a long time. What do these results really mean, though? Is it possible that people are just worse at noticing the subtler effects of the other drugs, or are just much worse at disciplining themselves enough to correctly use the racetams or noopept (as in, with choline)?
How much potential is there in innovation in nootropics? What is holding this innovation back, if anything? It feels like there hasn't been any real progress over the last 15 years (other than massively increased awareness), but could targeted drug discovery (along with people willing to be super-liberal with their experimentation) finally lead to some real breakthroughs?