1 · Evidence for a claim
Does the evidence match this formula and result?
We identify the exact finished formula, use site, outcome, population and time period. A study of an ingredient, another formula or a whole routine does not establish what this individual serum did.
When a full report is available, reviewers examine its comparison, methods, results, uncertainty, limitations and funding. Having a report to appraise does not mean it found a benefit.
2 · Shopping facts
What does the listed purchase include?
We check the one-time bottle price, package size and native unit, stock, seller, shipping, tax, subscription or membership terms, and return conditions where available.
A price per mL can help compare compatible liquid serums. We do not invent a 28-day cost without reliable product-specific usage information, or convert grams to mL without a supported basis.
How a product earns a pick
A pick answers a specific shopping question, such as which eligible listing has the lower bottle price in a defined group.
Step 1
Set the group
Compare the same kind of product and offer, with exact package, seller and market details.
Step 2
Check the rule and sources
Use a stated feature or price measure, current evidence, and a clear tie rule. Unknown terms remain unknown.
Step 3
Show the tradeoff
Keep the relevant evidence state, purchase limits and listing date beside the pick. Recheck or withdraw it when a required source expires.
Evidence labels, not grades
These plain labels describe what can be reviewed. They are not a ladder from bad to good and do not predict results.
- Methods available for appraisal
- An exact-formula human comparison report includes methods and results for review. This label says nothing about whether the result was positive.
- Limited methods report
- A test is described, but important methods or results are missing. We attribute the report and explain what cannot be checked.
- Public study not located
- A bounded search did not find an exact-formula human outcome study. That does not mean no study exists or the product does not work.
- Formula unidentified
- We cannot establish which finished formula was marketed or tested, so we do not draw a finished-product conclusion.
- Intervention or claim unmatched
- Testing concerns a combined routine, a different formula or another result. We identify that boundary rather than assigning the finding to one serum.
- Needs recheck
- Evidence is stale, conflicting or mismatched. We withdraw only the finding that depends on it until it is reviewed.
Questions readers often ask
Can a study of a routine tell us what one serum did?
Not by itself. If people used shampoo, conditioner and serum together, the result belongs to that routine. We do not assign it to the serum alone or to a different outcome, such as hair regrowth.
What does “safety source reviewed” mean?
It means we checked a source such as the product label for stated directions or cautions. It does not mean independent testing established the finished product is safe for everyone. We describe relevant substantiated cautions without turning personal tolerance into a universal safe or unsafe label.
Do a higher percentage, certificate or country prove better results?
No. A product name may describe a supplier blend rather than the amount of pure peptide. A raw-material certificate or country of origin does not establish how the finished bottle performs. We do not award a concentration bonus when the amount is unknown.
Do customer reviews establish effectiveness or the rate of side effects?
No. Sourced reviews can help us notice reports about packaging, texture, billing or experiences worth checking. Self-selected reviews cannot establish clinical results or how often an experience occurs.
What happens when a report is incomplete or a product changes?
We keep the evidence conclusion separate from whether methods were available. Conclusions can be not appraised, supported within stated limits, no demonstrated difference, inconclusive or a concerning signal. A new or changed formula needs an identity check before older findings carry over. Missing public evidence is not proof that a product failed.
What is public about the method?
We publish the assessment’s purpose, scope, evidence labels, shopping rules and source basis so readers can understand our decisions. Detailed working notes, calibration experiments and confidential provider correspondence stay internal. Cosmetic products currently receive no numeric score. Affiliate relationships do not change facts or picks.
What guides this approach?
We match health-related benefit claims to evidence and identify what a source can support. Our separation of product evidence from shopping facts is an editorial choice. See the FTC health-products guidance, the FDA MoCRA overview and the FDA cosmetic-labeling summary. These sources do not approve our assessment method.
What this method can and cannot tell you
We can describe the evidence we found for a specific claim and the purchase facts supported by dated sources. We cannot infer that one serum works better from a different formula’s study, ingredient theory, listing details or a feature pick. Product and source dates are shown separately from this method’s update date.
Our cosmetic evidence labels are separate from peptide or medicine claim grades. For peptide claim grading, see the evidence-grading method. Medicine cash-plan ratings answer a different shopping question and use their own scoped method; cosmetic products do not inherit those weights. Read the medicine-offer method.