Nootropics

Piracetam is the original "nootropic". C. Giurgea developed it in the late 1960s and coined the word to describe it. It is licensed in several countries for cognitive disorders, vertigo and cortical myoclonus. The evidence is mixed. An older meta-analysis found a global benefit in older adults with cognitive impairment, but a 2024 meta-analysis could not confirm an effect on memory.

Modafinil is a prescription wakefulness-promoting drug for narcolepsy, obstructive sleep apnoea and shift work sleep disorder. It is widely used off-label as a "smart drug". In healthy people who are not sleep-deprived, a meta-analysis found only a small overall cognitive effect, driven mainly by memory updating.

Alpha-GPC (choline alfoscerate) is a choline-containing phospholipid breakdown product, sold as a prescription drug in some countries and a supplement elsewhere. It is a precursor of both choline and acetylcholine. Its record is unusually mixed. One very large Korean cohort linked it to lower dementia conversion, while another linked it to higher 10-year stroke risk.

Citicoline (CDP-choline) is an intermediate in the synthesis of phosphatidylcholine, the main phospholipid in cell membranes. It is a prescription drug in some countries and a supplement in others. A meta-analysis found it improved cognitive status in mild cognitive impairment, Alzheimer's disease and post-stroke dementia, though the underlying studies were of poor quality.

Bacopa monnieri is an Ayurvedic herb used traditionally to support memory. Randomised trials in healthy older adults found better verbal learning and delayed recall after about 12 weeks. A meta-analysis of nine trials found faster attention (Trail B) and choice reaction time. It is slow to act and commonly causes gut side effects.

Caffeine is the world's most widely used psychoactive compound, a methylxanthine that works by blocking adenosine receptors. At low to moderate doses it reliably improves alertness, vigilance, attention and reaction time, with weaker and less consistent effects on memory and higher-order judgement. It is the reference point every other stimulant on this wiki gets compared to.

L-theanine is an amino acid found almost only in tea. Taken at 200 to 400 mg a day, it may reduce stress and anxiety in people under stressful conditions. Its best-known use is alongside caffeine, where the pair improves attention switching more than either alone. A 2025 meta-analysis found small improvements in subjective sleep.

Rhodiola rosea is an Arctic and alpine herb marketed as an adaptogen for stress and fatigue. Some randomised trials report less mental fatigue, but one found it made fatigue worse. Systematic reviews describe the evidence as contradictory and the trials as poorly reported.