Nootropics range from well-studied single compounds to complex multi-ingredient stacks. Choosing effectively requires matching the specific cognitive benefit you need with ingredients that have human trial data β not just animal or in-vitro studies.
- Citicoline (CDP-Choline): 250β500 mg/day improved attention and focus in healthy adults in a 2015 Journal of Attention Disorders trial. Also supports phospholipid synthesis for long-term brain health.
- Lion's Mane (Hericium erinaceus): 500β3,000 mg/day of fruiting body extract improved cognitive function in adults with mild cognitive impairment in a 2009 Phytotherapy Research RCT. Look for extracts standardized to beta-glucans (>25%).
- Bacopa monnieri: 300 mg/day (standardized to 50% bacosides) improved memory acquisition and retention after 12 weeks in a 2014 meta-analysis in Journal of Ethnopharmacology. Effects require consistent use β not acute.
- L-Theanine + Caffeine: The 100 mg L-theanine / 50 mg caffeine stack is one of the most replicated nootropic combinations. A 2008 Nutritional Neuroscience study showed improved accuracy on attention-switching tasks and reduced susceptibility to distraction.
- Phosphatidylserine (PS): 100β300 mg/day improved memory and cognitive function in older adults across several trials. Soy-derived PS is the most studied form.
- Racetams sold as supplements (piracetam, aniracetam) β these are unregulated drugs in most countries, not dietary supplements
- Mega-dose caffeine stacks marketed as "brain boosters" β cognitive benefits plateau above 200 mg
- Products listing "proprietary nootropic matrix" with 15+ ingredients at unknown doses
- Any product claiming to "permanently increase IQ"
For focus and attention: citicoline + caffeine + L-theanine. For memory and learning: bacopa + lion's mane (requires 8+ weeks). For stress-related cognitive decline: ashwagandha + phosphatidylserine. For long-term brain health: lion's mane + omega-3 DHA.