Studies and tests in cosmetics: essential terminology

Clinically tested indicates that the product’s efficacy has been evaluated in a controlled study involving human participants. Unlike dermatological testing, which focuses on safety, clinical testing measures quantifiable performance outcomes such as hydration levels, wrinkle depth, elasticity, or brightness, providing evidence that the product works as claimed.

Simple analogy:

・Dermatologically tested = This product is unlikely to harm your skin
・Clinically tested = This product is proven to improve your skin as claimed

Why the confusion?
Many brands conduct a clinical safety study, which is, technically, a type of clinical test for safety_._ However, a robust clinically tested claim should involve separate studies measuring specific performance outcomes.
Demand more from brands claiming clinically tested products. Often, these claims are not backed by the actual tests, but unfortunately, specific regulations do not protect consumers equally in all parts of the world.

Term

What it typically means

Common test type

Dermatologically tested

Primary focus – safety & compatibility

The finished product has been tested on human skin, under dermatological supervision, to assess its potential to cause irritation, redness, or allergic reactions. It confirms the product is safe and gentle for skin contact.

Repeat Insult Patch Test (RIPT), Human Repeat Insult Patch Test (HRIPT), under a dermatologist’s oversight.

Clinically tested

Primary focus – efficacy & performance

The finished product has been tested in a controlled clinical study to measure its effectiveness in delivering specific, claimed benefits (e.g., “increases hydration by 20%”, “reduces the appearance of fine lines”). It confirms the product works as advertised.

Consumer perception studies, instrumental measurements (e.g., corneometry for hydration, visioface for wrinkles), often conducted by a third-party lab or research clinic.

Clinical studies vs. consumer perception studies

Consumer perception studies

Consumer perception studies are surveys. A group of people use a product for a set period of time, then answer questions about their experience. Did their skin feel softer? Did they notice a difference? Do they like the texture?

Consumer perception studies are conducted as follows:

・ Participants receive the product and use it as directed, typically for 2–4 weeks.
・ Participants then complete questionnaires rating their experience with statements like “My skin felt more hydrated” or “I noticed reduced redness”.
・ Results are tabulated as percentages: “82% agreed their skin felt more hydrated”.

What the results actually tell you:
These studies measure subjective experience, i.e. how people felt about the product. They’re valuable for understanding sensory appeal, user satisfaction, and whether people enjoy using the product enough to keep buying it. However, these results don’t measure physiological changes in the skin. They tell you what people think happened, not what objectively did happen. And here comes the “breaking news”: of course your skin felt smoother after applying a cream. That’s what a cream does.

Clinical studies

Clinical studies use scientific instruments and trained evaluators to measure actual changes in the skin. They’re conducted in controlled environments with standardized protocols:

・ Participants follow a strict protocol with regular visits to the testing facility.
・ Measurements are taken at baseline (before starting) and at regular intervals using calibrated instruments.
・ Common measurements include: corneometer (measures skin hydration levels), cutometer (measures skin firmness and elasticity), visia or similar imaging (tracks changes in pigmentation, texture, and wrinkles).
・ Many studies are randomized, controlled, and sometimes blinded to eliminate bias.

What the results actually tell you:
These studies provide objective data about what the product actually does to skin physiology. When a study shows “hydration increased by 49%”, that’s a corneometer reading – it’s not someone’s opinion.

Beware of marketing traps

Consumer studies tell you: “People enjoyed using this product and thought it worked”.
Clinical studies tell you: “This product measurably changed skin physiology”.

And remember: any properly formulated moisturizer contains humectants (to attract water) and occlusives (to seal it in). Apply it, and your skin immediately feels softer and smoother. That’s not proof of efficacy – it’s proof of physics. When a brand boasts “95% of users felt smoother skin after application”, they’re essentially saying “95% of users experienced the intended function of a moisturizer”. It’s like running a perception study on umbrellas and announcing “92% of participants stayed dry in the rain”. Duh. That’s what it’s designed to do.

The marketing version sounds impressive. The honest version asks: What else happened? Did it actually strengthen your barrier over time? Did measurable hydration persist hours later? If a brand leads with immediate sensory claims and nothing else, ask yourself what they’re not telling you.