The first step to skin whitening: Inhibiting melanin production
Melanin is the primary pigment affecting skin whiteness, so inhibiting its production is naturally the most important ultimate goal of whitening products. Melanin is produced within melanocytes, which are located in the basal layer of the epidermis. Therefore, these functional ingredients must penetrate the skin and reach the basal layer to exert their effects. This is a relatively difficult problem to solve because the natural barrier of the stratum corneum is difficult to penetrate.
The second step to skin whitening: Blocking melanin transport
After melanin is produced within melanocytes, melanosomes are transported along the dendritic processes of the melanocytes to surrounding keratinocytes, affecting skin color. Melanin transport inhibitors can slow down the rate at which melanosomes are transferred to keratinocytes, reducing the melanin content in each epidermal cell layer, thus achieving a whitening effect.
The third step in whitening is exfoliation. These substances soften the stratum corneum, accelerate the shedding of dead cells, and promote epidermal metabolism. This causes melanosomes that have entered the epidermis to shed during the rapid renewal of the epidermis, thus reducing their impact on skin color. Examples include glycolic acid and keratinolytic enzymes.
