Every figure quoted across this desk's pieces, with where it came from and who was studied; the longer pieces name their sources in the text. A population column is there because a number from one group of people is not a number about another.
Choline intake
| The claim | Source | Population |
|---|---|---|
| Habitual choline intake in the US remains below the Adequate Intake. | Trujillo-Gonzalez et al., American Journal of Clinical Nutrition, 2026 | US adults |
| Only 10% of participants met the Adequate Intake for choline. | Suzuki et al., Journal of Food Composition and Analysis, 2025 | n=203, aged 65 and over |
Search volume
| The claim | Source | Population |
|---|---|---|
| "Brain fog" is searched roughly 60,500 times a month in the United States. | Google Keyword Planner, US monthly search volume, pulled August 2026 | US Google searches |
Alpha-GPC
| The claim | Source | Population |
|---|---|---|
| Research in healthy adults has used single doses of roughly 250–630 mg. | Nutrients 2024 (315 and 630 mg, Stroop task); a 2017 dose-comparison at 250 and 500 mg (Marcus et al., J Int Soc Sports Nutr, 2017); a 2023 crossover in J Int Soc Sports Nutr in 30 trained cyclists (300 mg) | Healthy adults |
| Higher-dose trials at 800–1,200 mg exist, in a different population. | Sohn et al. 2026 (1,200 mg); a traumatic brain injury trial | Diagnosed cognitive impairment — never cited here as a target for a healthy adult |
| Alpha-GPC can cross the blood–brain barrier. | Putri et al., Neuropsychiatric Disease and Treatment, 2026 (narrative review) | Review-level evidence — stated softly for that reason |
Choline bitartrate
| The claim | Source | Population |
|---|---|---|
| In one 2026 trial in healthy postmenopausal women, bitartrate did not improve working memory against placebo. | Dumas et al. 2026 (n=20, 1,650 mg): no working-memory performance difference against placebo. Brain activation did change, which is why the wording is "has not shown the benefits" and not "does not reach the brain". | n=20 healthy postmenopausal women |
Lion's mane
| The claim | Source | Population |
|---|---|---|
| Trials in healthy adults used 1.8 to 3.2 g a day — several times the amount in a typical capsule product. | Saitsu et al., Biomedical Research, 2019 (3.2 g, 12 weeks); Docherty et al., Nutrients, 2023 (1.8 g, 28 days) | Healthy adults, n=31 and n=41 |
| The one healthy-adult trial points both ways: a faster interference task after a single dose, and word recall significantly worse than placebo in the same session. | Docherty et al., Nutrients, 2023 | n=41 healthy adults, 28 days |
| A beta-glucan percentage is a specification, not a result on a certificate — it is a separate assay from the identity, heavy-metal and microbial panels a lot certificate usually carries. | Method note; assay by enzymatic (Megazyme) determination rather than a polysaccharide figure | Applies to any mushroom extract label |
L-theanine
| The claim | Source | Population |
|---|---|---|
| 200 mg is the amount most of the pooled trials used. | Pooled across the controlled trials in healthy adults; the amount most commonly dosed | Healthy adults |
| Percentage improvements from Hidese 2019 are not printed, because they were not significant against placebo on the paper's own between-arm test. | Hidese et al., Nutrients, 2019 | n=30 — cited here only to explain why the figures are absent |
Zinc and vitamin B12
| The claim | Source | Population |
|---|---|---|
| Zinc is required for the catalytic activity of approximately 100 enzymes. | NIH Office of Dietary Supplements, zinc fact sheet | General |
| Roughly 1 in 7 American adults falls short of the zinc they need from food, and more than a third of those over 60. | NHANES intake below the Estimated Average Requirement | US adults; the over-60 figure runs 35–45% |
| Vitamin B12 maintains the myelin around the nerves and supports normal nervous system function. | NIH Office of Dietary Supplements, vitamin B12 fact sheet | General |
| Oral B12 at 2,000 mcg matched injection in confirmed deficiency — a different question from an intake gap in someone without one. | Kuzminski et al., Blood, 1998 | Confirmed B12 deficiency — not a healthy adult |
What a certificate covers
| The claim | Source | Population |
|---|---|---|
| A lot certificate typically reports heavy metals and microbiology to published methods; per-active potency and a named beta-glucan assay are separate tests and are often absent. | Method note; heavy metals by ICP-MS, microbiology to the ISO series | Applies to any supplement certificate |
| "Third-party tested" is not a defined term and carries no fixed panel — the useful question is which tests, by whom, against which lot. | 21 CFR Part 111 sets manufacturing practice, not a testing seal | Applies to any supplement label |