If a substance improves certain cognitive metrics in healthy adults, then it qualifies a nootropic, even if it has harmful side effects. Purported nootropics ar

If a substance improves certain cognitive metrics in healthy adults, then it qualifies a nootropic, even if it has harmful side effects. Purported nootropics are often also marketed as, or alongside, purported life extension products. Maybe that creates some confusion about what nootropics are.