On August 1, 2022, National Institutes for Food and Drug Control (NIFDC) issued a notice on Issuing the Technical Guidelines for Anti-freckle and Whitening Cosmetics (Draft for Comments) (hereinafter referred to as Guidelines). The definition, mechanism, and compliance requirements of anti-freckle and whitening cosmetics have been further sorted out, which is of great reference for the future development and supervision of anti-freckle and whitening cosmetics.
The definition of anti-freckle and whitening cosmetics
According to the Classification Rules and Classification Catalogue of Cosmetics, there are three types of anti-freckle and whitening cosmetics:
Type 1: It helps to mitigate or slow down skin hyperpigmentation so as to achieve the effect of skin whitening;
Type 2: The whitening effect is only achieved through physical covering;
Type 3: It improves acne marks caused by pigmentation.
In the second type, the whitening effect of products achieved through temporary physical covering will be unable to really whiten the original skin color, and registration approval of these products shall be marked with "anti-freckle and whitening (only with physical covering effect)".
In addition, the Guidelines have mentioned that products with whitening effects through other mechanisms are not anti-freckle and whitening cosmetics. For example: cosmetics that brighten the skin or accelerate the renewal of exfoliation by improving hydration, cleaning, exfoliating, etc.; or products that only use sunscreen agents in the formula without adding anti-freckle and whitening agents.
The formation of melanin and the mechanism of whitening agents
It's better for us to first understand the formation of melanin so as to understand the main mechanism of action of anti-freckle and whitening cosmetics.
(In-depth study of the mechanism of melanin formation)
It can be seen from the above schematic diagram that the formation of melanin is a process in which a variety of substances are involved and gradually generated and accumulated. To achieve the whitening effect, the most effective method is to inhibit the production of melanin, therefore, we need to focus on the source of melanin which is "tyrosine". Tyrosine is an essential amino acid for nutrition, which plays an important role in the metabolism, growth, and development of humans and animals. Removal of tyrosine is clearly an "expensive" behavior.
1. Inhibits enzymes in melanin production
Throughout the production process, we found that tyrosinase is involved multiple times, promoting the final formation of melanin. Therefore, a major mechanism of whitening agents is to start with tyrosinase.
2. Reduction of oxidation products during melanin formation
The formation of melanin involves multiple oxidation reactions, for example, dopa is oxidized to form dopaquinone; DHI is oxidized to form eumelanin. It can also inhibit the production of melanin by inhibiting the oxidation of key substances such as dopa, and reducing the products in each oxidation reaction.
3. Inhibits the presentation of melanin in the epidermis of the skin
If melanin has been generated, we can still prevent melanosomes from being displayed on the skin epidermis by inhibiting the transport of melanosomes from the dermis to the corneum, thus preventing the skin from becoming dark.
In addition, it can also accelerate the excretion of melanin, exfoliate the cuticle, and reduce the ultraviolet radiation to achieve the "whitening" effect. However, we have mentioned at the beginning of the article that these mechanisms may not be regarded as anti-freckle and whitening products in the regulatory definition.
Whitening the skin through acid brushing and other methods is also not subject to the supervision as whitening products. Cosmetics with only physical covering effects refer to those added physical covering agents, such as titanium dioxide, zinc oxide, and other similar white powders, which can cover the spots on the skin so as to achieve a whitening effect by smearing and covering the skin surface, while the original appearance of the skin cannot be changed.
What are the commonly used whitening agents
According to the formation of melanin and the corresponding inhibition mechanism, "whitening agents" are usually divided into the following categories:
Claims related to anti-freckle and whitening
The efficacy claims of anti-freckle and whitening cosmetics should be scientific and reasonable with avoiding exaggeration. Claims on the efficacy of the mechanism of action of ingredients should be consistent with the efficacy basis of relevant ingredients.
① Claims should not use medical terms or words that imply the products have medical effects, such as removal of chloasma, lentigo, pigmented nevus, anti-inflammation, etc.;
② Exaggerated or absolute claims cannot be used, such as instant whitening, elimination of melanin, direct access to the bottom of the skin, intelligent inhibition of targeted darkening areas, etc.;
③ Products that only have sun protection, cleansing, and exfoliator efficacy without declaring as anti-freckle and whitening products are not allowed to directly claim their anti-freckle and whitening effects.
Supervision of anti-freckle and whitening cosmetics within the territory of China
According to the degree of safety risk of cosmetics in China, anti-freckle and whitening cosmetics are classified as special cosmetics, which are subject to registration management.
According to the Standard for the Evaluation of Efficacy Claims of Cosmetics, from January 1, 2022, human efficacy tests of newly registered anti-freckle and whitening cosmetics shall be conducted by the cosmetic registration and filing inspection agency in accordance with mandatory national standards and technical specifications with issuing the reports. Efficacy claim supporting documents shall be uploaded on the special website designated by the China NMPA.
Although an official "whitening agent list" has not yet been released in China, the Guidelines have stipulated that enterprises shall provide their own reports on the mechanism of action and efficacy of whitening agents during the registration process. The technical guidelines have not been officially released, but many enterprises have been required to submit supporting materials for anti-freckle and whitening agents during the registration process.