Evidence
How we read the evidence
The A–F grade answers a precise question — “what does the human evidence support for this use?” — it is not a purchase recommendation. Here is the study hierarchy and what each grade means.
Evidence hierarchy
- 01Meta-analyses & systematic reviews of human RCTs
- 02Well-powered, pre-registered RCTs with meaningful endpoints
- 03Smaller or surrogate-endpoint RCTs
- 04Prospective human cohort / observational data
- 05Mechanistic, animal or in-vitro — context only, never sufficient
Marketing, testimonials and manufacturer literature carry zero weight and are never cited as evidence.
A–F scale
54 graded entriesAConsistent high-quality human evidence supports the specific claim.2
BGood human evidence, with some limitations.10
CMixed or preliminary human evidence; plausible but unproven.40
DWeak, mostly indirect human evidence.1
ELittle credible human evidence for the claim as marketed.0
FEvidence contradicts the claim, or a safety concern dominates.1
Entries by grade
B10
C40
Alpha-lipoic acid (ALA)ApigeninAshwagandhaAstaxanthinBakuchiolBerberineCalcium alpha-ketoglutarate (Ca-AKG)Centella asiatica (Cica)Coenzyme Q10Collagen peptidesCurcuminErgothioneineFisetinGlycineGlyNAC (glycine + NAC)Green tea extract (EGCG)Hyaluronic acidL-CitrullineL-TheanineLion's ManeMagnesiumMelatoninN-Acetylcysteine (NAC)Omega-3 (EPA/DHA)Panthenol (provitamin B5)Peptides (topical)PHA (lactobionic acid)PQQ (Pyrroloquinoline quinone)PterostilbeneQuercetinResveratrolSulforaphaneTaurineTMG (Betaine)Urolithin AVitamin CVitamin DVitamin E (topical)Vitamin K2 (MK-7)Zinc
Method
How grades are assigned and why we stay independent →
Database
Browse every entry, filter and sort →
A grade is not medical advice or a purchase recommendation. The same molecule can hold different grades for different claims. Citations link to specific PubMed records where a PMID is verified; otherwise we use a scoped PubMed query and flag the entry as review-required.