Methodology
How we assess the evidence for supplement ingredients and rate products.
Evidence Levels (1–5)
Each ingredient is assigned an evidence level reflecting the quality and consistency of available human research. Level 1 is the strongest.
Strong evidence
Multiple consistent RCTs in humans. Meta-analyses available. Effect is well-replicated.
Moderate evidence
At least one solid RCT in humans. Effect is plausible but needs more replication.
Limited evidence
Observational studies or small RCTs only. Human evidence is preliminary.
Weak evidence
Animal or in vitro data only. No convincing human evidence.
No evidence
No relevant studies, or evidence is limited to testimonials and case reports.
Transparency Index (0–10)
Products are rated across five dimensions. The weighted composite score is the Transparency Index — a measure of how honestly and responsibly a product is presented, not of whether the ingredient works.
| Dimension | Weight |
|---|---|
| Evidence for ingredient How strong is the clinical evidence for the active ingredient? | 10% |
| Value for money Is the price per dose fair given available alternatives? | 30% |
| Product quality Form, standardisation, excipients, manufacturing standards. | 25% |
| Label honesty Are doses and claims accurately stated? No proprietary blends? | 20% |
| Third-party testing Is the product independently certified (Informed Sport, NSF, etc.)? | 15% |
Product Verdicts
≥ 7.0 / 10
Good evidence, fair price, honest label, and ideally third-party certified.
5.0 – 6.9 / 10
Decent product with some weaknesses — may still be a reasonable choice.
< 5.0 / 10
Significant shortcomings in at least one key dimension.
Claims Check Verdicts
For each marketing claim we check the underlying evidence and assign one of four verdicts.
The claim is backed by high-quality studies and is accurate in scope.
There is a real underlying effect, but the claim overstates its size or certainty.
The claim contradicts available evidence.
Preliminary findings exist but evidence is insufficient to draw conclusions.
EU Health Claims
Under EU Regulation (EC) No 1924/2006, health-related claims on food and supplement labels are only permitted if approved by EFSA (European Food Safety Authority) and listed in the EU Register of Authorised Health Claims.
The vast majority of longevity supplement ingredients (NMN, ashwagandha, resveratrol, etc.) have no approved EU health claims. This does not mean these ingredients have no effects — it means vendors cannot legally advertise health effects on EU labels.
We flag EFSA approval status on every ingredient dossier so you can distinguish between legally claimable effects and effects that are merely research findings.
Update frequency
Ingredient dossiers are reviewed when new relevant studies are published. Product ratings are updated when pricing, formulation, or certification status changes. Each page shows the last updated date.