Methodology

This page explains exactly how a product goes from “brand makes a claim” to “verdict published.” If a review doesn’t follow this process, that’s a bug — tell us.

Where claims come from

Every claim we evaluate is quoted verbatim from material the brand has published themselves — product packaging, the brand’s own product page, or other brand-controlled marketing. We link or screenshot the source at the time of review. We do not evaluate claims made by third parties (retailers, influencers) on the brand’s behalf unless the brand has directly endorsed them.

The verdict scale

• Supported by evidence — Published research on this ingredient, at a concentration consistent with this formulation, supports the specific claim being made.
• Plausible but unproven — The mechanism is scientifically reasonable and there is some supporting evidence, but no study directly supports the specific claim as worded, or the formulation’s exact concentration is unknown.
• Exaggerated — The underlying ingredient or mechanism has real evidence behind it, but the claim overstates the magnitude, speed, or certainty of the effect beyond what that evidence shows.
• No evidence — We could not find supporting research for this claim, for this ingredient, at any concentration.
• Contradicted by evidence — Published evidence, or our own testing of the product’s actual performance, directly conflicts with the claim.

How we weigh evidence

We prioritize peer-reviewed, published research — ideally in a recognized dermatology or cosmetic science journal — over brand-commissioned or unpublished studies. Where a claim rests on an ingredient’s general reputation rather than research on the actual formulation, we say so explicitly rather than letting the ingredient’s reputation stand in for the product’s.

Concentration matters more than presence. An ingredient with strong evidence at 5% tells you very little about a product where it’s listed sixteenth on the INCI list. We flag this distinction in the Evidence Strength section of every review.

What determines the Overall Verdict

Each review’s claims table is the actual record — every claim gets its own independent verdict. The single “Overall Verdict” shown at the top of a review is an editorial summary for scanning and filtering, weighted toward the product’s primary or most prominent marketing claim. It never overrides the per-claim detail below it.

Corrections

Formulations change, and so does the evidence base. Every review shows a “Last verified” date separate from its publish date. See our Editorial & Corrections Policy for how we handle updates and errors.