Usage test: sensory evaluation and actual performance of a cosmetic product
The usability test, sometimes called consumer use test, places the consumer at the center of the assessment. Instead of limiting itself to in vitro measurements or toxicological studies, it measures how the product actually performs when used in everyday life. This approach is essential for validating marketing claims and ensuring that the claims submitted to the Swiss and European authorities reflect the user's experience.
Implementation of the protocol
A panel of volunteers is selected based on the product's target audience: age, skin type, skincare habits, and any sensitivities. Each participant receives specific instructions: frequency of application (e.g., morning and evening), exact amount to use (half a pump or two grams), area of application (face, neck, décolleté), and total duration of the test, which can vary from seven days to four weeks depending on the nature of the product. The test environment is controlled: ambient temperature, humidity, and lighting are kept constant to reduce external variables.
Sensory evaluation criteria
Throughout the study period, volunteers rate several aspects of the product on standardized scales (usually from 1 to 5 or 1 to 7). The most common criteria include: texture (ease of spreading, feel of oiliness or lightness), smell (intensity, pleasantness, persistence), comfort (no tightness or stinging), speed of absorption, appearance of the skin after use (radiance, softness, appearance of pores), and overall perception of effectiveness.
Data collection and analysis
At the end of the test, each participant completes a detailed questionnaire that combines quantitative scores with open-ended comments. The responses are aggregated: the mean and standard deviation are calculated and, if necessary, statistical tests are performed to identify significant differences between criteria. A satisfaction rate of more than 70% on a key criterion (e.g., «pleasant texture») is generally considered sufficient to support a regulated claim.
Use of results
The data from the usage test is included in the Product Information File (PIF). It is used to:
- Justify allegations such as «pleasant to apply,» «immediate smoothing effect,» or «long-lasting comfort.».
- Optimize the formulation : The weaknesses identified (overpowering smell, sticky feel) will guide adjustments prior to commercial launch.
- Strengthen marketing messaging : Satisfaction figures (e.g., «98% of users find the texture soft») provide a strong selling point for consumers and distributors.
Added value of the usability test
In addition to providing scientific proof of the product's performance, the usage test adds a human dimension that complements safety assessments (DGT, COMET, TUNEL, etc.). It shows that the product is not only safe, but also pleasant to use, which is a decisive factor for commercial success in the Swiss, European, and UK markets, where claims must be supported by objective data.