Human hair color is determined by the presence and relative amounts of melanin pigments.
Types of Melanin in Hair
There are two main types of melanin responsible for hair color:
- Eumelanin: This pigment produces brown and black hair colors. The abundance of eumelanin dictates the darkness of the hair.
- Pheomelanin: This pigment contributes to red and yellow hair tones. The ratio of eumelanin to pheomelanin determines the overall hair color.
The amount and type of melanin produced are genetically determined and influence the resulting hair color, ranging from black and brown (high eumelanin) to red and blonde (high pheomelanin and low eumelanin). The absence of melanin results in gray or white hair.
Several sources confirm the presence of these pigments in human hair:
- MedlinePlus Genetics states that hair color is determined by the amount of melanin. An abundance of eumelanin leads to black or brown hair, while an abundance of pheomelanin results in red hair. https://medlineplus.gov/genetics/understanding/traits/haircolor/
- A study published in The Journal of Investigative Dermatology confirms the presence of both eumelanin and pheomelanin in human epidermis and, implicitly, in human hair. https://pubmed.ncbi.nlm.nih.gov/2071942/
- Multiple other sources, including articles from the American Chemical Society and Cleveland Clinic, corroborate the role of melanin in human hair pigmentation. https://pubs.acs.org/doi/full/10.1021/acscentsci.0c00068, https://my.clevelandclinic.org/health/body/22615-melanin
