Piracetam

Piracetam is the original 'nootropic' — the compound that gave the category its name — and is prescribed in several countries (though not the US) for conditions like myoclonus and certain cognitive complaints.

Its mechanism is diffuse rather than a single clean target: it's proposed to make neuronal membranes more fluid, to modulate AMPA and cholinergic signaling, and even to improve the flexibility of red blood cells and microcirculation.

Its evidence base is large but heterogeneous — decades of studies with mixed results — and it's approved abroad but not by the FDA, so its real-world reputation rests on a long but inconsistent record.