Moisturization remains one of the most important claims in the cosmetics industry. From facial creams to body lotions, a product’s ability to improve and maintain skin hydration is a key selling point. However, scientifically substantiating this efficacy requires a rigorous approach that combines instrumental methodologies, clinical assessments, and appropriate study designs.
The stratum corneum, the outermost layer of the epidermis, plays a crucial role in water retention and is responsible for approximately 90% of the skin’s barrier function. Skin hydration depends on the balance between water uptake, retention, and loss—a complex process influenced by both biological and environmental factors. As a result, evaluating moisturizing efficacy cannot rely on a single measurement or solely on consumer perception.
From a formulation perspective, moisturizers act through different mechanisms. Humectants attract water to the upper layers of the skin, increasing its moisture content. Emollients improve skin softness and flexibility, while occlusive agents reduce water evaporation by forming a protective film on the skin surface. Each of these mechanisms can generate different responses in instrumental measurements, making it essential to interpret results according to the type of product being evaluated.
In this context, biophysical instrumental techniques have become key tools for cosmetic claim substantiation. Among them, the assessment of the skin’s electrical properties is one of the most widely used approaches. Instruments such as the Corneometer® estimate superficial skin hydration by measuring skin capacitance. Since water has a significantly higher dielectric constant than other skin components, changes in capacitance correlate with variations in the water content of the stratum corneum.
Other technologies, such as the MoistureMeterD®, allow the assessment of water content at different skin depths, providing complementary information on skin hydration. This approach is particularly valuable for products targeting deeper hydration and for studies involving nutricosmetics.
One of the key lessons in cosmetic research is that no single method can fully describe the hydration status of the skin. Current best practice recommends a multiparametric approach combining different instrumental techniques, including transepidermal water loss (TEWL) measurements, skin texture and desquamation analysis, mechanical skin assessments, and imaging techniques. Integrating these parameters provides a more comprehensive and robust evaluation of product efficacy.
Study design also plays a critical role in the quality of the evidence generated. Single-application studies are useful for identifying immediate effects and can deliver results quickly and cost-effectively. However, they do not fully reflect real-life usage conditions. For this reason, many companies choose multiple-application studies conducted over several weeks, enabling the evaluation of product performance under conditions that more closely resemble everyday use.
Beyond traditional single-use and repeated-use studies, testing strategies can be tailored to the specific objectives of each product. For example, long-lasting studies are designed to demonstrate the duration of the moisturizing effect over several hours after application, while regression studies assess how long the benefits persist once product use has been discontinued. These study designs provide valuable evidence to support differentiated claims such as “24-hour hydration,” “long-lasting moisturization,” or “lasting improvement of skin dryness,” strengthening both product positioning and marketing communications.
Participant selection and study conditions are equally important. Factors such as age, baseline hydration levels, anatomical test site, and environmental conditions can significantly influence results. Maintaining controlled temperature and humidity conditions, standardizing cleansing habits, and implementing appropriate acclimatization procedures are essential to ensure data reliability and reproducibility.
In addition to instrumental measurements, clinical assessments provide valuable insight into the practical relevance of the results. Standardized dry skin scoring systems can evaluate visible signs such as scaling, roughness, redness, and cracks. Combining instrumental data with expert clinical evaluations generates stronger evidence aligned with the consumer experience.
For cosmetic brands, demonstrating moisturizing efficacy goes far beyond obtaining a favorable instrumental result. The real value lies in designing studies that generate evidence aligned with the product’s positioning strategy and intended marketing messages. Whether supporting claims related to immediate hydration, long-lasting efficacy, or improved barrier function, robust scientific data can transform a marketing promise into a genuine competitive advantage.
At Zurko Research, we develop customized testing protocols tailored to the specific needs of each project, combining instrumental methodologies, clinical evaluations, and specialized study designs such as long-lasting studies, regression studies, and trials involving dry or sensitive skin. Our goal is to help brands generate reliable, relevant, and commercially meaningful evidence that supports successful product launches and strengthens market positioning.
In an increasingly demanding market, where consumers, retailers, and regulatory bodies expect objective proof of efficacy, well-designed studies can make the difference between an ordinary launch and a product that truly stands out within its category. If you are developing a new moisturizer or strengthening the evidence behind an existing formulation, the Zurko Research team can help define the most appropriate testing strategy to maximize your product’s commercial potential.
CONTACT
Martín Carmen
Head of Business Development
carmen.martin@zurkoresearch.com
