feomelaniinia

Pheomelanin is a type of melanin pigment found in humans and animals. It is responsible for producing reddish and yellowish colors, contrasting with the darker browns and blacks produced by eumelanin. Pheomelanin is particularly abundant in the hair and skin of individuals with red hair and fair skin, but it is also present in lower amounts in other skin tones. The production of pheomelanin is influenced by genetic factors and exposure to ultraviolet (UV) radiation.

The chemical structure of pheomelanin is distinct from eumelanin, featuring benzothiazine derivatives rather than benzothiazole derivatives. This structural difference leads to its characteristic red-yellow hue. Pheomelanin plays a role in photoprotection, absorbing UV radiation, though it is generally considered less effective than eumelanin in this regard. In fact, higher concentrations of pheomelanin have been associated with an increased risk of skin damage from UV exposure, including sunburn and a greater susceptibility to developing melanoma, a type of skin cancer.

The balance between pheomelanin and eumelanin production is a key determinant of an individual's skin and hair color. Variations in the genes that control melanin synthesis, such as the melanocortin 1 receptor (MC1R) gene, can significantly impact the ratio of these pigments. For example, specific variants of the MC1R gene are strongly linked to the production of pheomelanin and the resulting red hair and fair skin phenotype.