When American Skincare Journal publishes a product evaluation, the ranking reflects months of laboratory measurement, clinical observation, and independent review. This page describes exactly how that process works, from the moment a product category is selected for evaluation through to the final published ranking. We publish this methodology so that readers can assess our work on its merits, not on our claims about it.
Product selection and procurement
We select product categories based on reader interest, market significance, and the availability of meaningful scientific criteria for evaluation. Within each category, we identify products through market research, dermatologist consultations, and published efficacy data. We aim to test a representative cross-section of available formulations, from widely distributed consumer brands to specialist products recommended by clinicians.
Every product is purchased anonymously at full retail price from the same channels available to consumers. No manufacturer is informed that a test is taking place, sends samples, or sees results before publication. This policy has no exceptions.
The evaluation framework
Each product is assessed according to a twelve-point evaluation system developed in consultation with our Scientific Advisory Panel. The criteria are fixed in writing before the first product is opened. They are not adjusted after results are known.
The twelve evaluation points are organized into four scoring pillars:
Proven effectiveness (40% of total score)
- Three-dimensional scanning measurement of wrinkle depth reduction across facial zones
- Collagen density analysis using calibrated cutometry
- Skin elasticity and firmness tracking over the full observation period
- Active ingredient concentration verified through independent laboratory assay
Skin safety (30% of total score)
- Dermatological patch testing for irritation and sensitization
- Clinical monitoring under real-world use conditions, including interaction with other common skincare products
- Allergological testing on participants with sensitive and reactive skin types
Application properties (20% of total score)
- Absorption rate measured on facial skin under controlled conditions
- Residue assessment, including compatibility with makeup application
- Spreadability and ease of use, evaluated by blinded participants
Claims verification (10% of total score)
- Systematic comparison of manufacturer marketing claims against measured results
- Transparency assessment: whether ingredient concentrations are disclosed and verifiable
Laboratory methods
Our laboratory measurements use standardized dermatological instruments, each calibrated according to the manufacturer’s specifications before every testing session. The principal instruments are:
Corneometer. Measures skin hydration levels by assessing the electrical capacitance of the stratum corneum. Readings are taken at standardized intervals over a twenty-four-hour period and again at weeks four, eight, and twelve.
Cutometer. Measures skin elasticity by applying controlled suction to a defined area of skin and recording the deformation and recovery curves. The R2 parameter (gross elasticity) is the primary metric, reflecting the skin’s ability to return to its original position.
3D profilometry. Creates a three-dimensional surface map of the skin, allowing precise quantification of wrinkle depth, volume, and surface area. Measurements are taken under standardized lighting and positioning to ensure reproducibility across sessions.
TEWL meter (transepidermal water loss). Measures the rate at which water escapes through the skin barrier. A reduction in TEWL indicates improved barrier function, one of the markers of skin health most relevant to aging.
Mexameter. Measures melanin and erythema indices, providing objective data on pigmentation changes and any inflammatory response to a product.
All laboratory procedures follow DIN EN ISO 22716, the international standard for good manufacturing practice in cosmetics, ensuring full reproducibility and objective comparison between products.
Observation timeline
We require a minimum six-month observation period for any anti-aging evaluation. This timeline reflects the biology of skin renewal. Surface hydration changes appear within days. Structural changes to collagen and elastin require weeks to become measurable. Cellular-level changes, where the most significant anti-aging mechanisms operate, require months of consistent use before they can be reliably assessed.
Formal measurements are recorded at four intervals: week four, week eight, week twelve, and week twenty-four. This schedule allows us to distinguish between products that deliver only short-term cosmetic improvements and those that produce sustained biological change. A product that shows strong results at week four but plateaus by week eight tells a fundamentally different story from one that continues improving through week twelve and beyond.
Participant protocols
Clinical observation involves adult participants who are experiencing measurable age-related skin changes. We do not test on young skin, because the question we are answering is whether a product works for the people who actually need it, not whether it performs well under ideal conditions.
Participants apply products according to the manufacturer’s instructions, twice daily unless otherwise specified. They are monitored by our clinical team throughout the observation period for adverse reactions, compliance, and any changes to their broader skincare routine that might confound results.
Independence and conflicts of interest
American Skincare Journal does not accept advertising from skincare brands. No manufacturer funds our testing, provides products, or has any influence over our methodology or conclusions. Our evaluations are funded entirely from editorial revenue.
Some product links on our site are affiliate links. If a reader purchases a product through one of these links, American Skincare Journal may receive a commission. This commission does not influence our ratings, our testing methodology, or our editorial conclusions in any way. The decision to include or exclude a product from a ranking is made before any commercial consideration is discussed.
Panel members disclose any prior professional relationship with a manufacturer whose product is under review. In the event of a conflict, the panel member recuses themselves from that evaluation.
Corrections
Our process is rigorous, but we are not infallible. If a reader, a manufacturer, or a member of the scientific community identifies a factual error in one of our evaluations, we investigate promptly. Substantiated corrections are applied to the published article with a dated note explaining the change. Material corrections that affect a product’s ranking are disclosed prominently.
Questions about our methodology or findings can be directed to our editorial team through the contact page.