Short answer
Most brands don't know skin can be tested this way: with nothing more than a piece of tape. Non-invasive skin testing measures molecules in the skin, usually proteins, to show how skin responds to a product. Samples are collected painlessly by tape sampling, using medical adhesive tape pressed onto the skin. They are then analysed in the lab to give objective, measurable results.
What is a skin biomarker?
A biomarker is a measurable biological signal. In skin, it is usually a protein or other molecule whose level tells you something about what the skin is doing. When skin becomes more hydrated, better protected or more inflamed, the amounts of certain proteins change, and those changes can be measured.
Examples of what skin biomarkers can reflect:
The skin barrier. Proteins that build and maintain the outer layer that keeps moisture in and irritants out.
Antioxidant Protection. Proteins that fight oxidative damage in the skin, brought on my UV damage, and cellular ageing.
Inflammation and stress. Proteins that rise when skin is irritated or under oxidative stress.
Ageing-related pathways. Proteins linked to how skin cells renew, repair and cope with damage over time.
Because these are measurements and not opinions, they are a different kind of evidence from how skin looks or how a person says it feels.
How samples are collected
Samples are taken by tape sampling: small pieces of medical adhesive tape pressed onto the skin and then peeled off. Each piece of tape lifts a thin layer of the outermost skin cells and the proteins they contain.
This matters for studies on real people, because it is:
Non-invasive.
Painless. Participants usually feel the tape lift off, and little else.
Repeatable. Samples can be taken before and after product use, at the same site, to see change over time.
A treatment group and a control group are sampled in the same way, so the two can be compared.
How samples are analysed
In the lab, the proteins are extracted from each piece of tape and measured by mass spectrometry. This technique identifies proteins by their mass and measures how much of each is present, and a modern workflow can read thousands of them in a single sample.
Two things make this approach different from a standard test:
It is an unbiased search. Many tests look for a short, preset list of markers chosen in advance. Mass spectrometry measures broadly, so the study can reveal changes nobody thought to look for.
It is quantitative. The result is a measured amount for each protein, which can be compared between treatment and control groups and across timepoints.
The analysis then turns thousands of measurements into a readable picture of which biological pathways moved, in which direction, and by how much.
What it can and cannot show
Biomarker testing is an incredibly powerful tool, but like any other technique, it has its limitations.
What it can show:
Whether a product changes biological pathways in real human skin, compared with a control
Which processes a product acts on, such as barrier, oxidative stress, inflammation or renewal
How those changes develop over time, if samples are taken at several points
Objective evidence that does not depend on opinion
What it cannot show on its own:
That a change will be visible or noticed by the user. A biological response frequently happens well before any visible change, so results do not tell you what a user will see or notice.
A claim to put on the bottle. Pack claims need evidence built around the exact claim wording, and biomarker data supports the science story around it.
Anything about layers of skin the tape does not reach. Mass spectrometry is a very powerful technique and can even sometimes detect collagen peptides in superficial samples, but it is unlikely to detect nuclear proteins, transcription factors or elastin from tape samples.
Treating the method honestly like this is what makes the data credible to scientists and buyers.
When brands use skin biomarker testing
Brands and ingredient makers use it when they need to show that a product or ingredient actually works, not only that people found it favourable.
Retailer and distributor pitches, to show a point of difference grounded in biology
Scientific storytelling for websites, decks and sales education
Peer-reviewed publication
Comparing formula versions, or checking that an active behaves in people as it did in the lab
Ingredient development, to show brands what an active does in human skin
It works alongside, not instead of, claims substantiation for the words on the pack. For a clear explanation of the difference, see Molecular evidence vs claims substantiation.
To discuss skin biomarker testing for your product, tell us about your formulation on the contact page.
This article is general information about a research method and is not a substitute for regulatory or legal advice.