How does hair get it's colour?

How does hair get it's colour

We have cells in the hair follicle known as "follicular melanocytes".

Melanocytes are our pigment producing cells. They are found in the skin and hair. Melanocytes make granules known as "melanin" and then transfer these to hair follicle keratinocytes. Pigment then accumulates in the growing hair shaft.

Melanocytes don't just make pigment whenever they want to. There is a complex communication between the cells of the bulb (the lower part of the follicle). Dermal papilla cells, melanocytes and keratinocytes all have a vote. Pigment is only produced in the anagen phase (growing phase) of the hair cycle.

When inflammation is present in the bulb, as in alopecia areata for example, the hair follicle does not always get properly pigmented. That is why patients with alopecia areata often regrow white hair.

By age 50, about 50% of us will notice that at least 50 % of our hair is grey. This appears to be due to a depletion of melanocyte stem cells that lead to fewer and fewer melanocytes being produced.