We know the cosmetics and personal care industry is a very dynamic and always evolving industry. The days of unclear claims with only marketing storytelling are gone, and the communication behind the product performance is experiencing a deep transformation driven by scientific innovation, increasingly demanding consumers for scientific credibility and transparency, and an evolving regulatory landscape.

A decade ago, I joined a French multinational Contract Research Organization (CRO) as part of the technical team specializing in the safety and efficacy testing of cosmetic products, working closely with multinational cosmetics brands in the design of testing protocols that ensure safety assessments and efficacy studies to meet regulatory requirements and substantiate product claims. Over the past ten years, this experience has allowed me to develop strong expertise in preclinical and clinical testing methods. Meanwhile, having worked at other CROs, I have witnessed firsthand the remarkable evolution of claim substantiation within the cosmetics industry. Nowadays, product safety and performance are no longer viewed merely as mandatory regulatory requirements; instead, they have become strategic tools that shape product innovation, brand credibility, and long-term consumer trust. In an era where consumers seek transparency, evidence, and authenticity, cosmetic products are expected to demonstrate not only excellent sensory appeal but also measurable biological benefits supported by robust scientific data.

This shift turns scientific substantiation from a Regulatory compliance requirement into a competitive advantage, helping brands make credible claims and stand out in a crowded market. From my perspective as a scientist, efficacy testing and science-based claims are not optional additions to product development; they represent the foundation of meaningful innovation. Rigorous testing methods transform marketing concepts into measurable biological outcomes, ensure consumer safety, product performance, and reinforce scientific integrity throughout the product lifecycle. In a market saturated with promises, scientific evidence is what elevates a cosmetic formulation from an attractive story to a scientifically credible solution capable of delivering real consumer value.

Product Safety: The Foundation of Consumer Trust

In our Cosmetics Industry, consumer safety remains the keystone of cosmetic product development and the first responsibility of every manufacturer placing products on the market. The EU Regulation (EC) No. 1223/2009 establishes one of the most comprehensive regulatory frameworks worldwide, ensuring that every cosmetic product placed on the market is safe for human health under normal or reasonably foreseeable conditions of use, as defined in Article 3 of the Regulation. To verify compliance with Article 3, manufacturers must complete a Cosmetic Product Safety Report (CPSR) as detailed in Annex I, before the item can be placed on the European market, detailed in Annex I, which requires an extensive scientific assessment of the formulation, toxicological profiles of ingredients, impurities, exposure scenarios, packaging interactions, and the final safety conclusion prepared by a qualified safety assessor.

Modern safety assessment integrates alternative methods that replace animal testing, combining sophisticated in vitro and ex vivo methods capable of evaluating skin irritation, corrosion, phototoxicity, eye irritation, sensitization pathways, and cellular toxicity using reconstructed human epidermis (RHE), human cell cultures, and ex vivo human skin explants. I worked in a UK-based GLP-accredited laboratory for completely animal-free safety testing. These technologies provide mechanistic insight into human skin biology while supporting ethical innovation and regulatory acceptance. They are often more predictive of human skin responses because they are based on human biology rather than interspecies extrapolation and predictive value for cosmetic product development and regulatory acceptance (OECD validated). Together, the animal-free safety testing establishes a scientifically robust foundation before a product reaches human volunteers, reducing development risks while accelerating innovation.

Although preclinical testing provides valuable mechanistic information, the demonstration of product safety ultimately requires confirmation under realistic conditions of human use. Following successful in vitro and ex vivo testing, cosmetic formulations undergo human skin compatibility studies to assess their tolerability, always in healthy volunteers. Preclinical safety assessment and acceptability testing under normal conditions of use, provide clinical evidence that supports the safety requirements established in Article 3 of Regulation (EC) No. 1223/2009. Human skin compatibility studies typically include occlusive or semi-occlusive Patch Tests designed to evaluate the skin irritation and sensitization potential of a cosmetic formulation under controlled conditions. Human Repeat Insult Patch Tests (HRIPT) are widely used to confirm skin compatibility and assess the likelihood of inducing allergic contact dermatitis following repeated exposure; these tests are conducted under dermatological supervision.

Subsequently, acceptability studies performed under normal conditions of use evaluate the product throughout its intended application period, allowing investigators to monitor adverse reactions, dermatological tolerance, and overall safety in real-life conditions. These studies directly support compliance with Article 3 of the EU Cosmetics Regulation by demonstrating that finished products remain safe during foreseeable consumer use. Importantly, safety evaluation has evolved far beyond a regulatory obligation. Brands increasingly recognize that transparent communication regarding testing strategies, dermatological validation, sensitive-skin compatibility, and ethical testing practices contributes significantly to consumer confidence. Safety is therefore becoming a strategic marketing value that reinforces corporate responsibility, supports premium positioning, and establishes long-term trust between consumers and cosmetic brands. Safety is becoming a brand asset rather than simply regulatory compliance.

Product Performance: From Biological Mechanisms to Consumer-Relevant Benefits

Once product safety has been demonstrated, scientific attention shifts toward proving that cosmetic products actually deliver their promised benefits. Consumers do not want just to see the phrase “Clinically Proven”, which means the product was used on a panel of people under normal conditions of use, since data robustness depends on the study design, or “Dermatologist Tested”, which means the panel was evaluated before and after the product use by a Dermatologist. Moreover, ophthalmological evaluation for products intended for periocular application is widely employed to confirm skin compatibility. The current generation of product innovation is increasingly driven by advances in skin and cellular biology, biotechnology, longevity research, microbiome science, and biotech biomimetic ingredients. Consequently, efficacy evaluation begins long before clinical evaluation through carefully designed preclinical studies that investigate biological mechanisms of action.

Preclinical testing in vitro methods allow researchers to quantify collagen synthesis, elastin production, extracellular matrix (ECM) remodelling, antioxidant activity, anti-inflammatory effects, epidermal barrier reinforcement, hydration, and pigmentation pathways, melanogenesis regulation, cellular renewal, and numerous molecular biomarkers associated with skin ageing and resilience. Complementary ex vivo models on human skin explants or 3D reconstructed human epidermis (RHE), preserve the complex architecture of the skin, allowing scientists to visualize the ingredient mechanism of action, tissue remodelling, skin differentiation (stratum corneum, epidermis, and dermis), protein and gene expression, and structural changes under physiologically relevant conditions. These mechanistic studies create a strong biological rationale linking ingredient activity to anticipated clinical benefits and provide robust scientific evidence supporting future product claims. Rather than relying on descriptive marketing communication alone, cosmetics brands are increasingly expected to demonstrate how ingredients interact with skin biology and contribute to measurable improvements in skin function.

Translating biological activity into measurable product performance

Nowadays, given that consumers are well-informed about the benefits of ingredients and their biological functions, mechanistic evidence alone is insufficient to substantiate cosmetic claims; they want to know the benefits under “real-life” conditions of use. Demonstrating product performance under real-life conditions requires carefully designed clinical trials and in vivo efficacy studies that translate biological activity into observable consumer benefits. Instrumental measurements performed during clinical evaluations provide objective and reproducible endpoints using validated technologies such as corneometry for skin hydration, transepidermal water loss (TEWL) measurements for barrier function, cutometry for elasticity and firmness, profilometry for wrinkle depth, colorimetry for pigmentation, high-resolution photography, three-dimensional skin imaging, ultrasound, optical coherence tomography, and confocal microscopy. These quantitative assessments are complemented by dermatologist evaluations and standardized clinical scoring systems that strengthen the scientific robustness of efficacy data.

Mintel's 2026 Global Beauty & Personal Care Predictions report moves beyond this year's trends to predict the themes shaping our industry by 2030 and beyond. This report presents a strategic framework that provides us with clarity regarding long-term consumer behaviours. They found that 78% of Brazilian adults agree that beauty brands should provide more scientific evidence to support the claims they make, like wrinkle reduction (Source: Mintel, March 2025). Additional data from the report highlights the importance of clinical studies. “Clinically-Proven” online conversations increased by 45% over a year (16,457 conversations), and conversations regarding “Science-Backed Skincare” grew by +37% (5,994 conversations).

Annex 1 of the Technical document on cosmetic claims according to Commission Regulation (EU) No 655/2013, claims on cosmetic products should conform to the following common criteria: 1. Legal compliance, 2. Truthfulness, 3. Evidential support, 4. Honesty, 5. Fairness, 6. Informed decision-making. Point 3 involves the appropriate efficacy testing methods for claims substantiation on cosmetic products; product performance must be supported by adequate and verifiable scientific evidence, including expert assessments.

The Sensorial Evolution: Sensorial Synergy

Equally important are consumer perception and sensorial studies, which assess product acceptance under normal conditions of use and capture subjective dimensions that instrumental measurements alone cannot fully describe. Texture, spreadability, absorption, fragrance perception, skin feel, comfort, freshness, and overall satisfaction influence purchasing decisions as much as measurable biological outcomes. Emerging concepts such as neurocosmetics and emotional efficacy further expand this perspective by recognizing that sensory experiences influence perceived product performance, emotional well-being, and consumer loyalty. Trends such as Mintel's Sensorial Synergy in the same report illustrate how neuroscience, psychodermatology, fragrance chemistry, and advanced texture design are becoming integrated into cosmetic research, enabling the evaluation of emotional endpoints, including relaxation, perceived stress reduction, mood enhancement, and overall wellness. Leading brands are integrating sensorial experiences and emotional well-being into beauty routines.

The increased need for emotional wellness makes 2026 the perfect moment for beauty’s sensory evolution. The Mintel report also noted that 36% of German facial skincare users believe that if a product causes a noticeable sensation on the skin, it is working (1,806 internet users aged 16+ who use a facial skincare product as part of their skincare routine). Now, the sensory experience is fully linked to product efficacy within the context of the "skin-brain axis" field! Product performance is therefore no longer defined exclusively by biological efficacy but by integrating objective scientific measurements with meaningful consumer experiences that reflect the holistic expectations of today's beauty consumer.

Conclusion

The cosmetics industry is undergoing a remarkable transition from compliance-driven product development toward science-led innovation focused on consumer trust. Safety and efficacy testing are no longer independent measures conducted simply to satisfy regulatory requirements; they have become strategic pillars that guide research and development, substantiate product claims, strengthen brand credibility, and support transparent communication. Mandatory safety assessment according to Regulation (EC) No. 1223/2009 and the requirements established in Annex I provide the essential foundation for consumer protection through integrated in vitro, ex vivo, and in vivo compatibility studies performed under normal or reasonably foreseeable conditions of use. Building upon this foundation, comprehensive efficacy testing, including mechanistic preclinical research, clinical trials, instrumental measurements, and consumer perception studies, enables manufacturers to demonstrate measurable product performance while supporting robust, science-based claims.

As consumers become increasingly informed and selective, cosmetic brands are expected to communicate with honesty, transparency, and evidence rather than relying on aspirational marketing language alone. Emerging concepts such as skin longevity, skin resilience, well-aging, microbiome modulation, neurocosmetics, and emotional efficacy illustrate the growing sophistication of cosmetic science and the need for multidimensional testing strategies capable of substantiating increasingly complex claims. From a scientific perspective, integrating testing strategies into the earliest stages of product development ensures not only regulatory compliance but also meaningful innovation capable of addressing genuine consumer needs.

Ultimately, science-based claims supported by rigorous safety and efficacy testing transform cosmetic products from marketing concepts into credible, high-value solutions that foster lasting consumer confidence. In an increasingly competitive beauty market, the brands that will lead the future are those that invest in scientific excellence, embrace transparency, and place evidence at the foundation of product development. By doing so, they move beyond regulatory compliance and position safety and efficacy testing as strategic marketing assets that create differentiation, strengthen trust, and deliver sustainable innovation for the next generation of cosmetic products.