Melanin is a dark brown pigment existing in animal skin or hair, which is produced by a special cell-melanocyte and stored in it. It is because of the existence of melanin that the skin has color.
Melanin is actually a kind of protein, which exists in everyone's body. They exist among cells in the basal layer of skin. At this time, they are not real melanin, but something called "melanin protoplasm", also called "pigment mother cells". Melanin is secreted by pigment mother cells. When ultraviolet rays (B wave and A wave) irradiate the skin (B wave is UVB acting on the basal layer of the skin, while A wave is more powerful, acting on the dermal layer of the skin), the skin will be in a state of "self-protection". Stimulate melanin by ultraviolet rays, activate tyrosinase activity and protect our skin cells. Tyrosinase reacts with tyrosine in the blood to produce a substance called dopa. Dopa is actually the precursor of melanin, which is oxidized by tyrosine and releases melanin. Melanin moves through the metabolic layer of cells, forming freckles, sunburns, dark spots and other shapes on the skin epidermis.
In this way, melanin is a substance produced by the skin to avoid being harmed by ultraviolet rays. From a certain point of view, he is a "good man", but his image is "poor". If the body's ability to synthesize melanin decreases, the skin will become sensitive. The incidence of skin cancer in many European countries is higher than that in African blacks, which is why. So melanin can protect our cells.
On how to inhibit the formation of melanin and whiten the skin, you can look at the following pages.