Melanin ( /ˈmɛlənɪn/ (listen); from Greek: μέλας melas, "black, dark") is a broad term for a group of natural pigments found in most organisms. Melanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the amino acid tyrosine is followed by polymerization.
Our skin color is determined by a pigment called melanin , and while everyone has melanin (both fair and dark-skinned people), it comes in different forms and ratios. The two forms of melanin are called eumelanin and pheomelanin. Eumelanin comes in primarily brown and black hues, while pheomelanin appears as red and yellow hues.
Skin color is often genetically determined. Differences in skin color result from the amount of melanin produced by the melanocytes and the size and distribution of the pigment granules . Melanocytes are melanin-producing cells located in the bottom layer (the stratum basale) of the skin's epidermis.
The primary function of melanin is in skin pigmentation. Melanin has other important roles in the human body such as, sunlight absorption and sun screening, protection from ultraviolet radiation, charge-transfer redox activity, free radical scavenging, antimicrobial immune defense, immunomodulation and ion chelating.