Redheads carry mutations in the gene known as Melanocortin 1 receptor (MC1R). Those with only a hint of red, including strawberry blond or auburn hair, may carry just a few MC1R mutations, while those with vibrant red hair may carry numerous mutations in the gene.

MC1R is responsible for producing the skin pigment melanin, which redheads can’t produce because of the mutation.  In order for a person to have red hair, both parents need to pass along a recessive genetic trait. To iterate, redheads inherit mutations in the melanocortin 1 receptor, or MC1R, on chromosome 16. 

The human MC1R is expressed on the surface of melanocytes and is a key regulator of intracellular signaling to the melanin biosynthetic pathway governing pigment formation.

The red hair phenotype results from excess pheomelanin production. Production of this yellow-red pigment results from well-described mutations of the MC1R.

In contrast, when a normal MC1R is expressed, the predominant pigment produced by melanocytes is eumelanin (dark brown) and the typical eumelanin to pheomelanin ratio is high.

This same gene is responsible for hair and skin color, but also for the midbrain function that determines pain response.

Who is This Type – Fitzpatrick Scale – Type 1

The red hair phenotype is characterized by fair skin color, freckles, and increased UV sensitivity.

Temperature changes

Redheads can easily detect changes in hot and cold temperatures.  Redheads are shown to be more sensitive to cold pain perception, cold pain tolerance, and heat pain.

Hair on Redheads

People with red hair have fewer strands of hair on their heads, just about 90,000 to the 110,000 for blonds and the 140,000 for dark-haired people. However, the individual strands are thicker, making their hair easier to style. Plus, redheads don’t go gray. The coppery color simply fades as the years wear on and eventually turns white.