The question I get most about brain supplements and drugs is about what works and what people should take.
The simplest way to classify a compound is to ask what happens after you stop taking it. If the benefit disappears within days, it was tuning the function of circuits that were already intact, which makes it a nootropic. If the benefit holds, the intervention changed something durable about the tissue, its connectivity, its vasculature, or its cellular state, which makes it neurorestorative.
Nootropics with best evidence in order:
- Caffeine: blocks adenosine receptors to reduce the sense of fatigue and raise arousal, and it has more controlled trials behind it than any other cognitive enhancer, which makes it the reliable choice for alertness and sustained attention.
- Caffeine with L-theanine: A 2025 meta-analysis of randomized trials found small-to-moderate improvements in attention and task switching.
- Prescription stimulants- In people without ADHD a meta-analysis of 48 placebo-controlled trials found only small effects on inhibitory control and memory, and its authors noted that much of what healthy users feel may be improved energy and motivation rather than faster thinking.
- Modafinil: A 2015 systematic review found measurable gains in attention and executive function in people who are not sleep deprived
- Guanfacine: its effect is clearest in ADHD and minimal in healthy people
- Creatine: A 2024 randomized trial found that a single high dose reduced the decline in processing speed and memory during overnight sleep deprivation, with a smaller effect in rested people.
- Bacopa monnieri: A meta-analysis of nine trials found improvements in memory and attention
- Nicotine: an agonist at nicotinic acetylcholine receptors, produces a measurable improvement in attention.
- L-tyrosine, citicoline, alpha-GPC, and the racetams have thinner support, though not none.
Neurorestoratives:
- Aerobic exercise: in a one-year randomized trial in older adults, a walking program increased anterior hippocampal volume by about 2 percent, while the same region shrank by about 1.4 percent in the control group.
- Speed-of-processing training: In the randomized ACTIVE trial in older adults it lowered the risk of dementia by roughly 29% over 10 years
- Mindfulness meditation and 3D video game training: controlled studies found gray matter increases on MRI
- Anti-amyloid antibodies: In phase 3 trials, lecanemab and donanemab slowed clinical decline in early Alzheimer’s
- B vitamins: In the VITACOG trial, high-dose B vitamins in older adults with mild cognitive impairment and elevated homocysteine reduced atrophy in the gray matter regions most vulnerable to Alzheimer’s disease 6. Omega-3: a 2025 analysis from the DO-HEALTH trial showed slowing of several DNA methylation agin clocks
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