What do "clinically tested" and "dermatologist tested" mean?
Less than they sound. "Clinically tested" means a product was tested on people. "Dermatologist tested" usually means a dermatologist oversaw a skin tolerance test. Neither term has a legal definition in the United States or Canada. The useful questions are what was measured, in how many people, and against what.
The common terms
| Term on the pack | What it usually means | What to ask |
|---|---|---|
| "Clinically tested" | Some test with human participants took place | The endpoint, the result, the number of people, whether the finished product was tested |
| "Dermatologist tested" | A dermatologist supervised or assessed a test, often for skin tolerance | Which benefit was measured, if any |
| "Clinically proven" | A claimed result from a study | Which result, how large, measured how |
| "Hypoallergenic" | The maker believes it is unlikely to cause allergy | Which test and threshold; the US sets no standard for the word |
| "Suitable for sensitive skin" | Often backed by a patch test on a panel | How sensitive the panel was, and how many people took part |
In the European Union, Regulation (EU) No 655/2013 sets common criteria that every cosmetic claim must meet, including evidential support and honesty. In the United States and Canada, advertising law requires a claim to be truthful and substantiated. None of these rules defines the words themselves.
Tolerance testing and efficacy testing
Many "dermatologist tested" claims rest on a tolerance study. The best-known is the repeat insult patch test (RIPT or HRIPT). A product is applied under a patch to the same site repeatedly over several weeks, then applied again after a rest period, to see whether skin becomes irritated or sensitized.
A result with no reactions tells you the product was well tolerated by that panel under those conditions. Hydration, firmness and tone are measured in efficacy studies. What patch testing involves: patch testing and declared allergens.
Instrumental versus self-assessed
Instrumental measurements use a device on the skin. A corneometer estimates surface hydration from electrical capacitance. A tewameter measures transepidermal water loss, a sign of barrier function. A cutometer measures elasticity. A chromameter or mexameter measures color. The device gives the same reading whoever holds the product.
Self-assessed results come from questionnaires: participants rate how their skin looks or feels. "Most participants said skin felt softer" is a real finding about perception, shaped by the question asked, the length of the study, and whether participants knew what they were using.
Both kinds of result are useful. They answer different questions, and a well-labeled claim tells you which kind it is.
Ingredient evidence versus product evidence
A study on an ingredient describes the ingredient. Research showing that hyaluronic acid binds water describes hyaluronic acid. What a particular serum does on skin, at its own concentration and in its own base, is measured on that serum.
This distinction is the basis of evidence grading. Vegalab grades every claim from A to D: A is published literature on an ingredient, B is internal formulation data, C is third-party testing of the finished product, D is clinical or regulatory validation. The framework in full: evidence levels. The methods behind each level: how we test.
Seven questions to ask about any study
- What was tested? The finished product, or an ingredient?
- What was measured? An instrument reading, a clinician's grading, or participants' opinions?
- How many people, and who? Skin type, age, and whether they match you.
- For how long? A result after one application differs from one after eight weeks.
- Against what? A placebo, the untreated side, another product, or nothing?
- Who ran it and who paid? A named laboratory, and whether the brand sponsored it.
- Is the full result available? Design, numbers and limitations, not only the best figure.
A claim that answers these questions carries its weight on the page. The claims on Vegalab pages, with their levels and sources: evidence hub.
Related reading
How ingredient lists work: how to read an ingredient list. What regulators do and do not review: how cosmetics are regulated. Professional questions on documentation: professional FAQ. More guides: Beauty Science knowledge.
Sources
- Commission Regulation (EU) No 655/2013 laying down common criteria for the justification of claims used in relation to cosmetic products.
- Federal Trade Commission Act, 15 U.S.C. 45 and 52 (unfair or deceptive acts; false advertisements).
- Health Canada, in conjunction with Advertising Standards Canada. Guidelines for Cosmetic Advertising and Labelling Claims.
- Competition Act, R.S.C. 1985, c. C-34, section 74.01.
Frequently asked questions
What does "clinically tested" mean on skincare?
That the product, or something related to it, was tested on people. The phrase has no legal definition in the United States or Canada. The questions to ask are what was measured, how many people took part, and what the result was. <!-- CLM-BS-0079 -->
What does "dermatologist tested" mean?
Usually that a dermatologist supervised or assessed a test, most often a skin tolerance or patch test. A benefit claim needs its own evidence.
Is "clinically proven" stronger than "clinically tested"?
It claims more: a demonstrated result, not only a test. Under US, Canadian and EU rules a claim of that kind needs evidence that supports it, so the question to ask is which result, measured how, in whom. <!-- CLM-BS-0079 -->
What is the difference between instrumental and self-assessed results?
An instrumental result is measured by a device, such as skin hydration by a corneometer. A self-assessed result is what participants reported in a questionnaire. Both are legitimate; a perception percentage reports what participants felt, and a device reading reports what was measured.
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