Magnesium is one of my favorite examples because everyone seems to LOVE magnesium. I like to talk about supplements and nootropics with people and many say they take magnesium and it helps them to feel calmer, sleep better, enjoy life, focus.
I just put it here because magnesium sounds like a nootropic, although what you say about absorption sounds pretty conclusive for it being placebo. I think the problem with a lot of these drugs is clinical trials are few and far between. Mainly because they would be classed as unethical.
Cg
imgo magnesium is really a nootropic and definitely NOT placebo.
but these "smart drugs" ARE coming and soon will be very popular....imho, they will be so used that ppl won't see them as unethical but necessary.