An evidence map · 56 entries
Most nootropic lists rank compounds by hype. This one asks a narrower question: for a given goal, what do human trials actually show? Pick a goal and every compound with graded human evidence lines up by how strong that evidence is and how big the effect was. The surprise is how often the boring entries win.
View 1 · everything at once
View 2 · one goal at a time
View 3 · side by side
Add up to four from any record. The columns line up their grades, doses, and timing, and the list below flags known or likely problems when they’re taken together. A missing flag is not a safety guarantee: it only means nothing on this page’s short list of interaction rules matched.
Read these first
Entries with a serious caution: dependence, dangerous withdrawal, liver injury, dangerous interactions, or legal risk. Some are legitimate prescriptions with real uses; the caution is about how they’re taken and what they’re combined with. Others are on the map because people ask about them, not because they’re a good idea.
Method and limits
Each square answers one question: for this goal, how much should the human evidence move you? Claude graded every compound on every goal against the rubric below, starting from Examine’s database (read in October 2026) and checking the key trials and meta-analyses directly. Where Claude’s grade matches Examine’s, the square shows theirs; where it differs or Examine has none, it’s marked † and hovering shows both. The Examine only tab shows their grades untouched, and Where Claude differs lists every change with its reason.
The rubric. A: a meta-analysis or at least three independent trials agreeing, about 300 people or more in total, from more than one research group, at low to moderate risk of bias. B: at least two agreeing trials with 100 or more people, or A-level evidence with one notable weakness (mostly one lab, country, or extract maker; inconsistent results; high risk of bias). C: one trial, a few small or inconsistent ones, or good evidence only in a distant population (children with ADHD don’t count toward adult focus). D: adequately sized trials that mostly found nothing. F: consistent evidence of harm, from trials or established side-effect data, whether or not Examine lists it. Only outcomes people feel or perform count; a lab marker such as cortisol counts only for inflammation. A combination is graded against placebo and takes its well-established ingredient’s grades where its own trials are thin. When unsure, Claude kept Examine’s grade. One exception, at Alex’s call: L-theanine keeps Examine’s A for stress and anxiety, though its trials total fewer than 300 people.
Trade-offs are separate from grades. A grade says how sure we can be that something works; the tags under each entry say what it costs to take: how fast it works, whether it’s habit-forming, how often users quit over side effects (from Nootroflix), and any F grades. An SSRI can earn an A and still carry heavy trade-offs; hydroxyzine can earn a C and be low-stakes to try.
User reports are kept separate. They come from open surveys of nootropic users and Gwern’s self-experiments. They capture what trials miss (how something feels day to day, whether people keep taking it) but they aren’t blinded, so they never feed into a grade.
How to read the user ratings. They answer a different question from the grades: not “does it beat placebo?” but “did people who chose to try it feel something?” Scott Alexander used choline, which barely reaches the brain, as a rough placebo benchmark; it rates 3.4 on Nootroflix, so anything near it may be mostly expectation. Individual experiences vary widely: in 2016 the typical spread was about 2.5 points for every compound, and a re-analysis that corrected for how each person uses the scale put one person’s likely result 2 to 3 points either side of the average. The same users rated more sleep (5.9), meditation (5.8), and weightlifting (6.7) above nearly every supplement here. Gwern’s notes add the rare thing surveys can’t: a single person testing compounds blind against placebo, often finding much less than he felt. Claude couldn’t read Reddit threads directly (Reddit blocks automated reading), and vendor reviews were too few and too uniformly five-star to add signal.
Three things the grades don’t tell you. First, a grade is about the people studied: many high grades come from older adults with cognitive decline or people with diagnosed depression. Turn on Healthy adults only to see how thin the evidence gets for an already healthy brain. Second, effect sizes in this field are usually small, even when the grade is high. Third, supplements are loosely regulated, so the bottle may not contain what the trial used: one analysis of melatonin products found doses from 83% less to 478% more than the label.
Fixing a gap beats adding a booster. Iron, B12, vitamin D, and magnesium mostly grade low or negligible for healthy people, but correcting a real deficiency can matter a great deal. That needs a blood test, not a guess.