Cos&Co is a consulting and training firm specialising in cosmetic performance evaluation strategy, founded by Pascale Barlier. It supports its clients in developing and implementing efficacy-testing strategies and designs clinical study protocols that allow claims to be substantiated robustly. Cos&Co is also involved in validating and rolling out new measurement tools alongside equipment manufacturers, and, through operational audits, supports clinical testing laboratories with their challenges and continuous- improvement needs. In addition, Cos&Co is a Qualiopi-certified training organisation, offering courses on cosmetic performance evaluation for professionals and students alike, covering the scientific, marketing and regulatory dimensions of the field.
I. How does regulation support the development of claims that are both scientifically sound and realistic?
Cosmetics regulation pursues one essential objective: protecting the consumer, both in terms of product safety and in terms of the fairness of the information conveyed to them.
While monitoring arrangements and regulatory frameworks vary from one country or region to another, the need to guarantee product safety and avoid misleading consumers remains a widely shared principle.
On top of these regulatory requirements, which differ from one country (the United States, Japan, South Korea, China, etc.) or geographic zone (Europe, ASEAN, etc.) to another, come recommendations, guidelines and self-regulatory mechanisms that help frame how cosmetic products are communicated about. A product claim should therefore not simply be attractive from a marketing standpoint: it must be consistent with the product’s actual characteristics, understandable to the consumer, and supported by evidence that is both relevant and sufficiently robust.
This requirement is also a matter of credibility and trust. The most reliable brands build the question of proof into their products from the earliest stages of development: which benefits should be claimed? Which parameters should be measured? Using what methods, on what population, and under what conditions? This approach establishes continuity between product design, its mechanism of action, performance evaluation, and the claims ultimately communicated to the consumer.
Regulatory oversight can also act as a driver of innovation. The need to demonstrate safety and justify the benefits claimed encourages every player in the value chain, ingredient suppliers, formulators, manufacturers, testing laboratories and brands alike, to invest in research and in new evaluation methodologies. This, in turn, deepens our understanding of the skin and its appendages, helps identify new biological targets and biomarkers, and drives the development of ever more powerful exploratory technologies (atomic force microscopy, polarimetric microscopy, multi-omics analysis, among others) built on a range of skin-sampling techniques (stripping, scrubbing, swabbing, interstitial fluid collection, VOC sensors, biosensors, and more).
Rather than a mere constraint, regulatory requirements can therefore become a genuine driver of scientific and methodological innovation, as well as a factor of differentiation in an industry that is particularly competitive on a global scale.
Striking the right balance between innovation, freedom of communication and consumer protection therefore remains a major challenge.
II. In a cosmetics industry under constant pressure to innovate, how can brands guarantee consumers robust product claims?
What exactly is meant by “robust evidence”? And how does each brand interpret this notion?
What does European regulation, which can largely be extrapolated to other regions, actually say?
- Every claim must be truthful, clear, fair, objective, and must not be misleading.
- It must rest on the weight of evidence drawn from the full body of studies, data and information available, in light of the nature of the claim and end users’ general level of understanding.
- Studies must have been conducted using reliable and reproducible methods.
The robustness of a piece of evidence does not rest on simply having conducted a study. It depends on the relevance of the experimental model, the methods and protocol used, the choice of evaluation criteria, the population studied, the control of variability factors, and the scientific interpretation of the results.
The real challenge, then, is to ensure consistency between the claim, the mechanism of action, the evaluation method, and the level of evidence obtained.
The most rigorous companies build the question of evidence into product development at a very early stage. Thinking no longer focuses solely on the formula or the choice of active ingredients, but also on how the benefits can be objectively substantiated: which parameters should be measured? Using what methodology? On what population? At what point in time, and under what conditions of use?
It is widely recognised that the ideal, most robust proof of product efficacy comes from objective instrumental studies on volunteers under real-life conditions of use, conditions that most closely mirror how a consumer actually uses the product.
But reaching this level of evidence takes both investment and time, and the risk of disappointing results is very real in vivo: skin responses vary from one person to another, effects can be moderate, and parameters are influenced by numerous factors. In short, the human subject, subject to multiple sources of variation, is constantly changing, and intra-individual variability sometimes exceeds the variation brought about by the product itself.
Competition has become so intense in recent years that manufacturers, in their drive to stand out, keep launching new products built around new claims. Imaging, cutaneous biophysics, biochemical and molecular analyses, in vitro, ex vivo and in vivo approaches, microbiome analysis and digital tools now make it possible to explore mechanisms and benefits that were barely accessible just a few years ago.
Competition also has a positive effect on cosmetic innovation: it pushes players to seek out new avenues of efficacy, new targets and new parameters worth exploring. Technological advances make it possible to identify new mechanisms of action and new molecules of interest, while deepening our understanding of the skin and its appendages. The development of in vitro, ex vivo and, increasingly, in silico models is opening up new possibilities for studying both active ingredients and finished products.
These preclinical studies are essential for documenting mechanisms of action, identifying potential effects and guiding the choice of parameters, methodologies and protocols to be used in vivo. In doing so, they help build a coherent body of evidence to support the claims made.
Without in vivo confirmation, however, it remains difficult to extrapolate benefits observed on a preclinical model to the consumer, except where robust correlations between preclinical and clinical data have already been established. The central question therefore remains: to what extent will an effect observed on a model translate into a real benefit for the consumer?
In such a highly competitive market, the temptation can be strong to scale back the level of demonstration in order to cut costs or meet a launch deadline. Some benefits are then claimed on the basis of minimal studies, or even solely on ingredients “known for…”, without sufficient demonstration on the finished product.
On top of this comes a degree of marketing escalation: scientific concepts turned into trends, ever more ambitious claims, storytelling and social media amplification, all of which can sometimes overshadow the underlying evidence.
Presenting science and figures is not enough on its own. Terms such as “in vitro”, “ex vivo”, “instrumental testing”, “clinical study” or “consumer testing” remain hard for a non-specialist to interpret. The challenge, then, is to make the evidence understandable and tangible for the consumer.
A genuine “digital passport of proof”, accessible via QR code, could offer a simple explanation of the studies conducted, their conditions and the relevance of the methods used. It would help give proper credit to brands that genuinely invest in scientific substantiation.
This approach calls for more consumer education, but also better training for future professionals in cosmetic performance evaluation, a subject that is still not widely taught. Ultimately, making evidence visible, legible and understandable would help distinguish a scientifically demonstrated claim from one that is merely asserted.
When a consumer’s real-world experience falls short of the benefits announced, it is not only the product in question that loses credibility. Over time, this accumulation of disappointing claims can help erode trust in the cosmetics sector as a whole.
III. How do you see in vivo evaluation practices evolving in the years ahead?
I see several major developments on the horizon.
First, better correlation between data from preclinical models (3D reconstructed skin models) and clinical study data should help optimise in vivo evaluations. Over time, some models could become predictive enough to reduce or ease reliance on certain in vivo tests, as already illustrated by the evolution of SPF evaluation methods through the new ISO standards.
To get there, however, the relationship between these two approaches still needs to be better characterised. Brands already frequently compare results from in vitro/ex vivo testing with those of clinical studies. This is a sound approach, but it too rarely rests on a genuine scientific demonstration of correlation between the quantitative data obtained.
Second, the development of the digital twin, already under way, should also accelerate with the rise of artificial intelligence, which will likely become an indispensable tool for modelling and prediction.
Another major development concerns the growth of portable, wearable measurement tools. Measurement is gradually moving out of the laboratory, allowing data to be collected under real-life conditions. The volunteer becomes more of an active participant in the study, since they can now collect and transmit certain data themselves, while still remaining under the laboratory’s methodological oversight and, in the future, potentially guided by digital assistants.
Patches, smartphones, watches and other connected devices can thus help track certain biomarkers, visualise the skin’s day-to-day evolution, assess how well a product holds up over time, or even collect data relating to emotional states. This development, however, hinges on one essential condition: having tools whose reliability and metrological performance have been scientifically demonstrated.
Reducing the need to travel to the laboratory also opens the door to studies deployed simultaneously across several countries or continents, particularly when the evaluation relies on connected devices or dedicated applications and requires different ethics panels.
These new approaches will complement, rather than replace, the exploratory studies carried out in the laboratory, which benefit from sophisticated instruments and tightly controlled experimental conditions. With that in mind, I believe it is essential to involve testing providers more closely in efforts to build robust bridges between preclinical and clinical data.
Overall, I see a profound shift in traditional in vivo evaluation practices, opening up new methodological perspectives and new angles of analysis. Testing laboratories will need to support this transformation by incorporating more digital, connected and decentralised methodologies.
But this technological shift should not make us lose sight of the fact that we are, above all, working for consumers. Their satisfaction, their perception and the sheer pleasure of using a cosmetic product remain essential dimensions. This subjective component, which complements objective measurements, must continue to hold an essential place in in vivo evaluations.
In closing, I would say that in a sector where consumers face a constant flood of messages and new claims, the ability to offer benefits that are realistic, understandable and scientifically demonstrated is, in my view, one of the most effective hallmarks a brand can build for its long-term success
