Methodology
Every A, B, C, and Emerging grade on this site is assigned against one rubric, applied the same way whether an ingredient ends up in Signal State Core or gets graded out. This page is that rubric, made public — not a claim about any ingredient's effect, and not a claim about the unlaunched product.
The five statuses
A, B, C, and Emerging are ordered by strength of human evidence, not by how promising an ingredient's story sounds. Graded Out is different in kind, not just in strength — it sits off that scale entirely. Here is what each one actually requires.
Strong — multiple human trials and consistent effects0 of 41 ingredients currently carry this status.
Moderate — several human trials, some mixed results16 of 41 ingredients currently carry this status.
Limited — early or small human trials16 of 41 ingredients currently carry this status.
Emerging — mostly preclinical or preliminary human data6 of 41 ingredients currently carry this status.
Graded out — evaluated and not featured (failed replication or a safety signal)3 of 41 ingredients currently carry this status.
Why nothing is a Grade A
Most stimulant-free cognitive ingredients simply don't have the multi-trial, right-population, consistent-effect evidence base that a caffeine-grade claim would need. Rather than lower the bar to fill the top grade, we leave it empty.
Right now every active ingredient under consideration for Signal State Core v1 clears Grade C or better — no lower grade is used for a cognitive active in the formula. Grade C and Emerging ingredients in the library are either excluded from v1 entirely, or included only for a separate, well-established non-cognitive role (see the foundational layer on the Ingredient Library).
We grade ingredients out
A brand that only shows you what it sells can't be second-guessed. We publish the ingredients we researched and chose not to use, with the same evidence note we'd give anything else.
Graded Out isn't the same as grading low. Some Grade C and Emerging ingredients stay in the library for education and comparison — they still have a real, if limited, positive signal. DMAE carries the Graded Out status specifically because the acetylcholine mechanism it's marketed on is poorly substantiated, its strongest positive human data is decades-old pediatric research since abandoned, a Cochrane review of the related cholinergic approach found no evidence of benefit, and a modern developmental-toxicity signal argues for avoidance rather than inclusion — a failed efficacy picture plus a safety veto, which fails the standard outright, not just the grade.
See every researched ingredient, in or out, in the Evidence Explorer, filtered by Graded out.
Claim-specific grading
Nuance is expressed through claim-specific grading, not plus/minus modifiers on a single letter — an ingredient can honestly grade differently depending on what it's being asked to do.
The same ingredient can carry a strong grade for one endpoint and a weak one for another, because the underlying trial base often supports one use far better than a different one. Panax ginseng is a clean example: an independent Cochrane review found no convincing evidence of a cognitive-enhancing effect, so this entry grades C for cognition — but a separate mental-fatigue signal exists for a different species, American ginseng (Panax quinquefolius), which is graded B on its own page for that narrower claim. Reading the American-ginseng fatigue grade across to Asian Panax ginseng cognition would be dishonest, so we don't. Rather than invent a “B+” or “C-” notation, we keep the letter grades simple and put the actual nuance in each ingredient's evidence note, scoped explicitly to the claim it supports.
Grading the claim, not just the ingredient
A grade attaches to a specific claim, because the underlying evidence often supports one use far better than another.
Stress and cortisol evidence is roughly Grade B — 60-day RCTs of standardized extract lowered perceived stress and serum cortisol versus placebo. The direct-cognition evidence is thinner and smaller, so the cognition-specific grade is honestly Evidence: Grade C.
Evidence is more consistent for symptomatic mild cognitive impairment than for healthy adults, where controlled trials are mixed and large prevention trials were negative — so for a healthy-adult use case the grade is Evidence: Grade C, not higher.
Most positive cognition trials are in dementia or post-stroke recovery populations, and a large observational cohort flagged a stroke-risk association — an association, not proven causation, but enough to keep a healthy-adult use case at Evidence: Grade C.
The persuasive trials used a bovine-cortex source in memory-impaired older adults; a direct RCT of the soy-derived form actually used in modern supplements — including this formula — failed to beat placebo at 300 or 600 mg/day. Wrong source, wrong population: a still-reasonable inclusion, but honestly Evidence: Grade C, not the grade the older trials might suggest.
Studied dose vs. label dose
Every ingredient page states a studied dose range — what human research actually used — separately from any dose a real product might carry. A high grade at 500 mg says nothing about a product carrying 50 mg.
“Fairy dusting” — including an ingredient at a fraction of its studied dose so it can appear on a label without meaningfully contributing — is the most common way a legitimate evidence grade gets borrowed for a formula that doesn't deserve it. We treat studied dose as part of the grade, not a footnote: check the dose transparency breakdown in Ingredient count vs. studied dose, and check any ingredient's own studied range on its library page.
FAQ
A grade from A to Emerging is our own conservative reading of the published human research behind a single ingredient, for the specific claim we're discussing — not a product claim, a promise of effect, or a regulatory approval.
A is reserved for multiple independent human trials, in the right population, with a consistent effect and no safety flags — a bar nothing in our current library clears. Right now the library tops out at Grade B (5 ingredients), with most entries at C or Emerging.
Graded Out is its own evidence status, not just a low grade. It means we researched an ingredient to the same standard as everything else and it actively failed that standard — either the dominant evidence is a failed replication or a null result on independent review, or a safety signal vetoes it regardless of how the efficacy data reads. It doesn't sit on the A–Emerging strength scale at all. DMAE is the clearest example: a poorly substantiated mechanism, no adequate positive human data in healthy adults, and an animal developmental-toxicity signal.
A studied dose is the amount used in the actual research behind an ingredient. A label dose is what a product actually delivers per serving. If the label dose is well below the studied dose, the ingredient's evidence grade doesn't transfer to the product — that's why every ingredient page states a studied dose range, not a recommendation.
Yes. Each ingredient page carries an updated date, and a grade is revisited as new trials, meta-analyses, or safety data appear — it isn't a one-time label.
See the standard applied to every ingredient in the Evidence Explorer, read the full Ingredient Library, or see how grading connects to what we will and won't claim in the Claims Policy.