The Science of Hair Greying: Genetics and Environmental Factors

Hair color is determined by melanin, produced by melanocytes in hair follicles. Two types of melanin, eumelanin and pheomelanin, blend to create a range of hair colors from black to red.

Genetics largely dictate when you'll start going grey. A key gene, IRF4, is associated with melanin production and hair color, influencing the onset of greying.

As we age, melanocytes slow down and eventually stop producing melanin. The result is hair that looks grey, which is actually transparent and reflects light.

Our hair cells produce small amounts of hydrogen peroxide. Over time, this builds up and bleaches the hair from the inside out, leading to grey strands.

Stress can hasten the depletion of melanin in hair follicles. Hormonal changes during stress may damage melanocytes, contributing to premature greying.

Exposure to UV light, pollutants, and certain chemicals can accelerate the decline of melanocyte activity, leading to earlier greying of hair.

While most grey hair is irreversible, addressing deficiencies in B vitamins, particularly B12, may restore color if greying is due to a deficiency-related condition.

Hair naturally provides some UV protection to the scalp, but grey hair offers less protection due to reduced melanin.