pheomelanin

noun

pheo·​mel·​a·​nin ˌfē-ə-ˈme-lə-nən 

variants or less commonly phaeomelanin

plural pheomelanins also phaeomelanins

: a reddish-yellow sulfur-containing melanin pigment formed in the presence of cysteine

… in people with dark brown or black hair, the pheomelanin is effectively masked by the darker eumelanin.

—Erin Brodwin

The marked spectrum of color and diversity of patterns … in mammals arises, unexpectedly, from variation in the quantity, quality, and regional distribution of just two types of pigment—black eumelanin and yellow pheomelanin.

—Sophie I. Candille et al.

compare eumelanin, neuromelanin

Examples of pheomelanin in a Sentence

Recent Examples on the Web

High pheomelanin and low eumelanin tend to produce light skin and freckles/red hair (very high pheomelanin) or yellow hair. —Heather Jones, Verywell Health, 1 Aug. 2024

No or very little eumelanin or pheomelanin (albinism) tends to produce pale skin/white hair. —Heather Jones, Verywell Health, 1 Aug. 2024

The melanin in your hair can exist in two main types: eumelanin (black melanin) and pheomelanin (orange-red melanin). —Anna Giorgi, Verywell Health, 10 July 2024

Slater and her colleagues went looking for ginger shades in the fossil record because evidence of pheomelanins has shown up there far less often than the researchers expected, compared with modern-day animals. —Riley Black, Scientific American, 14 Dec. 2023

While eumelanin and pheomelanin control the colors of such visible characteristics, neuromelanin affects neurons in the brain and plays a role in protection against neurodegenerative disorders such as Parkinson's disease. —Daryl Austin, USA TODAY, 1 Sep. 2023

There are three basic types of the pigment: eumelanin, pheomelanin and neuromelanin. —Daryl Austin, USA TODAY, 1 Sep. 2023

Gray and brown colors, for their parts, appear to arise from combinations of eumelanin, pheomelanin and pigment absence. —Jakob Vinther, Scientific American, 1 Mar. 2017

Researchers involved in the study believe that the earliest humans had pale skin containing pheomelanin, as do our close relatives, the chimpanzees. —Gemma Tarlach, Discover Magazine, 26 Feb. 2014

Word History

Etymology

borrowed from German Phäomelanin, from Greek phaiós "a shade between black and white, gray, dark gray" (of obscure origin) + Melanin melanin

Note: The term Phäomelanin was apparently introduced, along with Eumelanin eumelanin, by the biologist Karl Görnitz in "Versuch einer Klassifikation der häufigsten Federfärbungen," Journal für Ornithologie, Band 71 (1923), Heft 1, pp. 127-31. On the meaning of the element phäo-/pheo- see the note at pheochromocytoma.

First Known Use

1924, in the meaning defined above

Medical Definition

pheomelanin

noun

pheo·​mel·​a·​nin

variants also phaeomelanin

ˌfē-ə-ˈmel-ə-nən 

: a reddish-yellow sulfur-containing melanin pigment formed in the presence of cysteine

As pH reduces, there is a progressive reduction in tyrosinase activity leading to increased pheomelanin and reddish or blonde hair.

—Anagha Kumar et al., International Journal of Trichology

Modern melanosomes generally carry a mixture of two melanin pigments: dark brown-black eumelanin and red-yellow pheomelanin.

—Meghan Rosen, Science News

The marked spectrum of color and diversity of patterns that we see in mammals arises, unexpectedly, from variation in the quantity, quality, and regional distribution of just two types of pigment—black eumelanin and yellow pheomelanin.

—Sophie I. Candille et al., Science

compare eumelanin, neuromelanin