Companies can no longer rely purely on their marketing claims. With the development of ways to measure cosmetic and personal care effects they can now backup their claims.
Until the 1950s most efficacy tests were subjective, but now instrumental methods have been created including in-vitro and in-vivo measurements on human volunteers. Instrumental evaluation is often used in an attempt to provide data to support claims commonly associated with the reversal of the signs of ageing due to intense scrutiny from both the regulators and competitors.
Other claims that frequently receive pressure are related to the increased moisture levels in skin, improvements in skin texture, elasticity and smoothness. Nor are claims restricted to cosmetic effects on skin. Hair properties are also measured, such as improvements in hair strength and styling products that retain their properties. Deodorants are also regularly measured with regards to their odor protection effectiveness and duration.
However, a cosmetic scientist may have a different understanding of what is meant by the product claim than that of a consumer. Therefore, it is important to understand different terms and their scientific meaning when reading product claims. Here is a short list of terms and how they are measured:
Hydration – A measure of the water content of the skin via the analysis of the moisture retention capacity based on the dielectric constant of the water present in the skins layers.
Firmness & Elasticity – The ability to resist skin deformation and return the skin to its natural state. It utilizes a probe suction method that measures the resistance of the skin to be sucked up by the negative pressure thereby measuring firmness and its ability to return to its original position measures elasticity.
A different approach uses a device that applies a twisting motion to the skin surface. When the torque is released the time taken for the skin to return to its normal state is measured and this is related to skin elasticity.
Wrinkles – A measurement of the wrinkles depth and width using dermatologic imaging analysis.
Deep lines & wrinkles – The method for measuring deeper lines and wrinkles is based on shadows on a silicon replica of the skin which is then analyzed by software which measures different characteristics of the wrinkle in length, depth and shape.
Pigmentation – To measure skin colouring and imperfections diffuse reflectance spectroscopy is used for determining the concentration of skin chromophores, melanin and haemoglobin by observing the absorption spectra.
Odor – Deodorant efficacy is evaluated by sensory assessments, also known as a “sniff test” performed by an expert panel. The panel assesses the intensity of body odor developing in the armpits of 10 to 30 persons after cleansing over the course of 24 h. In one armpit, no deodorant is used, in the other, the test deodorant is applied. The intensity of body odor is scored from 0 = none to 5 = very intensive, and is recorded every 6 h und normal activities of the test persons without intermittent washing. The difference of the average score between the two sides is the basis for the evaluation of efficacy. If there is a significant difference between the treated and untreated side after 24 h, the efficacy is proven.
Other tests are more related to the quality of the products such as hardness testing of lipsticks, flow characteristics of powders and emolliency and slip of creams and lotions. The testing of SPF, UVA and antioxidant capacity of sunscreens is another important area that warrants its own article. The testing of hair products also lends itself to extensive instrumental testing.
The cost of the instruments, the difficulty of assembling a suitable panel of volunteers and of performing clinical trials is beyond the means and abilities of many companies so the use of a third party testing company is recommended. There are numerous testing companies located throughout the World, some which have a special focus or expertise in a certain type of clinical trial.
In conclusion, as there are many third party efficacy testing houses readily available and affordable there should be no reason that a company makes a competitively advantageous statement without verification. So, don’t just trust marketing jargon, trust independent certification.