How can you tell if a cream that brightens the complexion really delivers on its promises? If a foundation gives you a healthy glow? Or if an ingredient really does even out your skin tone? At a time when scientific proof and performance have become essential requirements in the world of cosmetics and personal care, scientific evaluation of products has never been more important. In contemporary cosmetics, “radiance” has become worldwide one of the most popular claims.
The Korean Wave (Hallyu) has propelled “the ideal radiant complexion” onto the global stage, redefining this claim through an intricate fusion of skin conditions, healthy appearance and eternal youth. As if beauty transcends aesthetics, reflecting a holistic philosophy centered on self-care and well-being.
Consumers are increasingly looking for skin that appears luminous, fresh, and vibrant. A new vocabulary of glow, luminosity, shine, clarity and transparency now dominates communication around skincare, replacing older narratives focused solely on correction of flaws. Radiance is inherently subjective, shaped by optical interactions between light and the skin as well as by perceptual and cultural factors. However, in clinical objectivation studies, subjective descriptors must not only be adapted to the cultural sensitivity of consumers but also be translated into measurable results in order to validate the product’s effectiveness.
Skin radiance is widely considered a key indicator of skin health and, increasingly, of an individual’s overall health. Unlike parameters such as hydration, elasticity or pigmentation, which are well-defined and quantifiable physiological characteristics, skin radiance results from the interaction of biological, optical and perceptual determinants.
As Mathieu Hébert (Optical Institute Graduate School) noted during the Skin Biology Workshop (September 12; CED-Lyon biopôle), “the radiance is difficult to define in terms of physical measurement even if every expert gives his own definition.
Beauty is perceived in a more integrative way: it encompasses skin quality, lifestyle, well-being, and emotional balance. In this holistic vision, radiance embodies both visible proof of skin health and a symbolic expression of vitality. What people expect from radiance-enhancing skincare is not only measurable improvement but also emotional pleasure, sensoriality and an overall boost to their self-esteem.
FROM 35TH IFSCC CONGRESS
Cosmetic evaluation, as demonstrated at the IFSCC Congress 2025, held in Cannes last September, is undergoing a decisive transformation from traditional endpoints of safety and efficacy towards multidimensional paradigms that integrate consumer-relevant outcomes. Among these, the measurement of skin radiance has emerged as a critical frontier, transcending subjective perception to become a scientifically objectified parameter of cutaneous vitality. Advances in vivo methods, combined with AI-driven imaging, multispectral analysis, spectral mapping, biometric analysis, and subjects’ insights, enable precise characterization of luminosity, translucency, and light diffusion within the skin. These methodologies, further supported by holistic in-vivo studies, not only capture radiance as an aesthetic outcome but also correlate it with underlying biological processes such as hydration, barrier integrity, and microcirculatory dynamics. By anchoring radiance assessment in rigorous experimental frameworks while aligning it with consumer expectations of visible performance, personalization, the field is consolidating its scientific credibility and expanding the evidentiary base of cosmetic claims. Discussions on climatic adaptation underscored that radiance is profoundly context dependent. Pollution, UV exposure, and humidity levels influence light scattering and translucency. Incorporating regional environmental factors into radiance testing will be essential for ensuring global relevance of claims, especially in diverse populations with variable baseline luminosity. Full-spectrum protection against UV, visible, and infrared radiation is crucial not only for preventing cellular damage but also for maintaining optical clarity and preventing dullness. The speculative but visionary discussions on space exploration also included considerations of microgravity and cosmic radiation. Space extreme conditions may compromise circulation, hydration, and barrier function, thereby altering radiance. It can interrogate radiance resilience, potentially generating insights transferrable to terrestrial challenges such as urban pollution and oxidative stress. At the IFSCC congress, radiance unifies disparate research domains under a framework of measurable, visible, and biologically grounded vitality. Its integration into testing paradigms not only reinforces the scientific credibility of cosmetic claims but also ensures alignment with consumer expectations of luminosity, health, and well-being. By elevating radiance from perception to quantifiable science, the cosmetic industry signals its readiness to embrace new horizons where biology, technology, and consumer aspiration converge.
THE EXPOSOME AND ITS IMPACT ON SKIN LUMINOSITY
The biological and environmental determinants of radiance are now better understood. Skin appearance is influenced by both intrinsic factors (genetics, skin structure, pigmentation patterns, vascularization) and extrinsic factors grouped under the concept of the exposome. These include sun exposure, pollution, nutrition, stress, and lifestyle habits.
Radiance results from complex optical interactions between light and the skin’s surface and structures. Parameters such as epidermal thickness, micro-relief organisation, stratum corneum quality, melanin distribution, collagen network organisation in the dermis, microcirculation, imperfections, pore size, and hydration status all affect the way incident light is absorbed, scattered, and reflected. Disruptions in these parameters such as uneven pigmentation, roughness, or redness, reduce the perception of skin tone homogeneity and radiance, creating a duller or more tired appearance.
Skincare products claim to improve radiance typically act on one or several of these mechanisms: restoring hydration, smoothing the surface, enhancing microcirculation, or evening skin tone. Some incorporate optical agents to instantly boost light reflection, while others target long-term biological pathways such as melanogenesis or dermal renewal.
THE PERCEPTION OF RADIANCE
Radiance is more than a visual quality; it is also an emotional and social signal. Studies show that a radiant complexion is associated with attractiveness, vitality, and even perceived health. Neuroscience has demonstrated that exposure to radiant skin images can trigger positive emotional responses, linking cosmetics not only to physical improvement but also to psychological well-being. This highlights the importance of integrating both perceptual and emotional outcomes into skin radiance live evaluations among biometrological assessment. Beyond measurable optical parameters, radiance conveys a feeling of freshness and vitality that resonates deeply with consumers
In an increasingly inclusive world, it should be noted that skin brightness assessment must consider different skin types, as it is certain that the results obtained on a European, American, South American or African subject will not be the same in terms of both results and interpretation. Furthermore, given the importance of global pollution, the measurement of skin radiance should be considered in conditions that mimic consumers’ real lives in order to both protect and cleanse the skin as effectively as possible from external aggressions.
RADIANCE EVALUATION: FROM PERCEPTION TO INSTRUMENTAL MEASURES
The perception of skin tone, its evenness and radiance vary according to culture and individual sensitivity. This assessment depends on our cultural and social preconceptions. Isn’t tanning itself subject to relative appreciation depending on the era, social class and culture? For instance, Asian consumers often emphasize transparency and even tone as components of radiance, while Western markets highlight glow and luminous complexion.
The subjective nature of brightness makes it difficult to assess. In studies involving volunteers, whether clinical protocols with expert assessment or biometric measurements, descriptors such as ‘bright’ or ‘luminous’ must be translated into intelligible, meaningful and reproducible results. The in vivo assessment of skin radiance relies on the use of various methodologies:
- Consumer tests with self-assessment by subjects reflect users’ perception of the product. Participants report their perception of radiance using structured questionnaires and rating scales. These tests capture the subjective improvement consumers expect and are essential for claim substantiation.
- Clinical evaluation by scoring: semi-quantitative rating by qualified evaluators.
Dermatologists or trained cosmetologists grade radiance using validated scales under standardized lighting and photographic conditions. This reduces, but does not eliminate, subjectivity.
- Sensory analysis by a trained panel.
- Neurosensory measurements: capturing unconscious or emotional reactions.
Emerging methods such as facial expression analysis, eye-tracking, or EEG measure unconscious reactions to radiant skin. These tools provide insight into the emotional value of radiance and its role in attractiveness and well-being.
- Biometrological measurement: objective and instrumental measurements of the skin’s optical properties. A wide range of optical and imaging devices can objectively quantify radiance.
The combination of these approaches provides a multidimensional assessment of skin radiance and evenness, linking consumer perception to optical reality.
Because of its importance to both consumers and clinicians, methods for assessing skin radiance have gained increasing attention in cosmetic science and dermatological research. Traditional approaches, expert visual grading or consumer self-assessment, offer valuable insights but are limited by subjectivity and inter-observer variability. Advances in imaging and biophysical instrumentation now allow for more objective quantification of radiance through spectrophotometry, colorimetric analysis, gloss measurements, multispectral imaging, and digital image processing. These tools yield standardized, reproducible metrics that can be correlated with physiological parameters such as hydration, vascularization, or microcirculation, thereby bridging perceptual beauty with measurable biology.
A rigorous assessment of radiance requires compliance with scientific standards, the latest technological advances and current regulations. Efficacy studies must comply with regulations in force in different regions of the world, with European cosmetics complying with the common guidelines of the Product Information File (PIF). In Europe, in order to validate cosmetic claims, it is essential to comply with six common criteria (legal compliance, truthfulness, supporting evidence, honesty and safety, fairness and impartiality, informed decision-making), although there are specific standards for sensory analysis. Product performance evaluation involves a multi-sensory, sometimes neurosensory, and holistic approach, as the impact on quality of life, sensations and feelings can also be objectified.
It is essential for investigators to collaborate closely with CROs to meticulously design protocols, define inclusion criteria, establish measurement timelines, treatment conditions, and select optimal devices. Investing time in briefing these essential elements is never wasted; it ensures the integrity and reliability of the study outcomes.
| Study parameters | Devices & methods |
| Color by image | Antera 3D, C-Cube Clinical Research, ColorFace |
| Skin renewal and desquamation | Quantisquame |
| Full face: overall analysis | ColorFace, Cydolia 3D Acquisition System, DynaCam, HeadScan Dynamics III, HeadScan V05 – R&D, VISA-CR – Gen 2 and 5, VISIA Complexion Analysis |
| Skin surface, relief and topography | Epsilon, DermaTOP-HE-60, SpectraCam, Visioscan, MoistureMap MM 100, C-Cube, TiVi 60 Skin Damage Visualizer, Antera 3D, Visia CR, Clarity 3D Mini, Neo Voir II, SIAScope, Videomicroscope, Dermascope, DermLite DL100, Videometer Lab, VEOS DS3, DermaLab Videoscope, SpectraCam, SpectraFace. |
| Skin radiance measure | GonioLux, Glossymeter, SambaFace, Skin Transluency, SkinGlossMeter |
| Global aspect and holistic approach | Visual and tactile objectivation with Scoring by experts and using specific scales and photos, Sensory and neurosensory analysis by trained panels or naïve subjects, Emotions evaluation by I.A, Consumer testing |
Claims Related to Radiance
Radiance encompasses a wide range of cosmetic claims, reflecting both the optical properties of the skin and its perceived vitality. Common claims include “brightening” or “luminosity enhancement,” which indicate an improvement in skin tone uniformity and a reduction in dullness; “glow” or “healthy-looking skin,” emphasizing the overall visual freshness and vibrancy of the complexion; “even complexion” or “tone correction,” addressing heterogeneities such as pigmentation spots or redness; and “translucency” or “clarity,” referring to the skin’s ability to transmit and reflect light evenly. Other claims may focus on surface smoothness or micro-relief refinement, which improve light diffusion and thus perceived radiance, as well as hydration-related radiance, linking moisture levels to a luminous appearance. More recently, claims have also included emotional or perceptual benefits, such as a feeling of vitality, freshness, or skin “energy,” reflecting the recognition that radiance is both a visual and psychological phenomenon. In clinical evaluation, each of these claims requires specific measurement endpoints—ranging from instrumental optical assessments to consumer perception studies—to ensure reproducibility, scientific validity, and regulatory compliance.
Radiance and the Role of Exfoliation
Exfoliation is a critical mechanism for enhancing skin radiance, as it removes dead surface cells, smooths micro-relief, and promotes the renewal of the epidermis. By clearing the outermost layer of the stratum corneum, exfoliation improves light reflection and diffusion, leading to a brighter, more luminous complexion. Many cosmetic claims related to radiance specifically highlight “surface refinement”, “glow improvement”, or “skin clarity”, which are directly influenced by exfoliating treatments. Exfoliation can be achieved through physical methods (microbeads, scrubs, or brushes) or chemical agents (alpha- and beta-hydroxy acids, enzymes), each with distinct mechanisms and effects on skin smoothness. Importantly, clinical evaluation of radiance often monitors the impact of exfoliation on parameters such as surface roughness, luminosity, and tone uniformity, using both instrumental measurements and expert or consumer perception assessments. By integrating exfoliation into radiance-enhancing routines, skincare products can provide immediate optical benefits as well as long-term improvements in epidermal health and radiance.
Radiance, social media and Gen Z
The concept of “radiance,” usually associated with vitality, health, and personal well-being, is increasingly mediated by social media, particularly among Generation Z. Platforms such as Instagram, TikTok, and Snapchat emphasize visual storytelling, where curated images, filters, and short videos shape perceptions of attractiveness, confidence,and self-presentation. For Generation Z, radiance extends beyond physicalappearance, encompassing lifestyle, digital engagement, and consumer practices, with likes, comments, and shares functioning as social indicators that validate certain aesthetic and behavioral norms. Cosmetics play a central role in this construction of radiance, as skincare, supplements, and wellness items are both promoted and consumed through social media channels.
Influencer endorsements, user generated reviews, and viral trends reinforce the idea that radiance and glow can be achieved or enhanced through specific products, creating a feedback loop where personal identity, social validation, and consumption intersect.
Understanding this interplay is crucial for examining how digital environments shape youth culture, self-perception, & emerging patterns of consumer behavior.
CONCLUSION
The concept of radiance has evolved into a key factor of modern cosmetic science. It integrates biological, optical, and perceptual factors, making its evaluation both complex and essential. Clinical assessment of radiance requires a multi-layered approach: subjective consumer tests, expert visual scoring, neuro-sensory analyses, and instrumental biometrology.
By combining these methodologies in standardized and reproducible protocols, researchers can bridge the gap between perception and physiological parameters. This not only enhances the credibility of cosmetic claims but also provides consumers with scientifically validated products that improve both appearance and well-being.
Among the neurosensory approach, 2D or 3D skin imaging and optical analysis of its surface are becoming crucial, and various techniques are seeking ever higher resolution, larger measurement areas, and instantaneous, contactless, and direct methods. AI-assisted algorithms and statistics will be the main contributors to the future success of these new technologies. Regardless of the type of measurement, biometric techniques prioritize accurate data acquisition, optimal repositioning, high resolution, fast capture times and automated rotation systems to ensure accuracy.
Among these, skin radiance emerged as a pivotal concept, reframed from a subjective impression into an objectifiable scientific parameter. Radiance served as a unifying lens through which weak signals and future-oriented research trajectories were examined, linking molecular innovation with consumer-centric performance. Radiance is positioned not merely as aesthetic but as a biomarker of skin health.
