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.

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.

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.

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.