What the research says about nootropics
Reference entries for 160 substances, from caffeine and L-theanine to racetams and prescription stimulants. Each entry grades the evidence behind every claimed benefit, gives the dose range used in studies, lists known side effects and legal status in four jurisdictions, and links to the papers.
Or browse all 160 substances or compare two side by side. New to the subject? Start with what nootropics are.
Where to start
Full index| Substance | Class | Evidence | Studied dose | Half-life | Safety | US status |
|---|---|---|---|---|---|---|
| Alpha-GPC | Cholinergic | A | 300-600mg | 6h | OTC | |
| Ashwagandha | Adaptogen | A | 300-600mg | 6h | OTC | |
| Bacopa Monnieri | Adaptogen | A | 300-600mg | 4h | OTC | |
| Caffeine | Stimulant | A | 50-400mg | 5h | OTC | |
| Creatine | Amino acid | A | 3000-5000mg | 3h | OTC | |
| Curcumin (Turmeric) | Neuroprotective | B | 500-2000mg | - | OTC | |
| L-Theanine | Amino acid | A | 100-400mg | 1h | OTC | |
| Lion's Mane | Adaptogen | B | 500-3000mg | 8h | OTC |
Tools
- Interaction checker
- Recorded interactions between any two or more substances, with severity.
- Stack builder
- Combine substances and see estimated cost, safety scores and interactions.
- Goal finder
- Stacks in the library for a goal, ranked by evidence grade and safety.
- Research browser
- Every graded benefit claim, filterable by grade and category.
How the site is run
Every substance entry follows the same record: grade, studied dose range, side effects with their frequency, legal status in the US, UK, EU and Australia, and the studies behind them. The grading scale and how the safety score is set are published on the methodology page.
The site earns money from affiliate links to vendors, paid vendor listings and its annual report. None of those change a grade, a safety score or what an entry says; the disclosures page lists them all.
Found a mistake? The corrections page explains how to report one and what happens next.
Stacks in the library
All stacks| Stack | Goal | Ingredients | Est. cost/day |
|---|---|---|---|
| Anxiety Reduction Stack | stress | Ashwagandha (KSM-66), L-Theanine, Magnesium Glycinate | $1.10 |
| Beginner Focus Stack | focus | Caffeine, L-Theanine, Bacopa Monnieri | $1.20 |
| Deep Work Stack | focus | Alpha-GPC, L-Tyrosine, Caffeine, L-Theanine | $2.80 |
| Evening Wind-down Stack | sleep | Magnesium L-Threonate, L-Theanine, Apigenin, Glycine | $1.30 |
| Longevity Brain Stack | longevity | Omega-3, Magnesium L-Threonate, Creatine, Taurine, Nicotinamide Riboside | $4.80 |
| Longevity Foundation Stack | longevity | Omega-3 (DHA-dominant), Vitamin D3, Magnesium Glycinate, Creatine Monohydrate, Vitamin K2 (MK-7) | $0.90 |