Gray hair biology 101

Gray Hair Biology 101

There’s no such thing, really, as “turning” gray. Color doesn’t fade away from the shaft; a gray hair has no color because the supply of pigment in the hair follicle itself is missing.

Hair fiber actually has no color; the cuticle, the outermost protective layer, is transparent. When we see a blonde or a brunette, we perceive color because the pigment shines through. Imagine if you could drain the pigment out, what would you see? No color at all.

This is what your body does for you. One of the natural amino acids in the body, tyrosine, is the “raw material” of melanin. But, somewhere along the way, you start running out of tyrosine. You do not have an infinite supply. So the cells stop producing melanin, and hair shows an absence of color, appearing gray, in contrast to darker shades of hair, or totally white in the absence of any reflective color at all.

Melanin production diminishes at its own rate. Usually in a random pattern at first, starting at your temples and top of your head. The blood vessels try their best to distribute tyrosine to the bottom of each hair follicle, but when supply is short, some follicles just won’t get it at all. You start to “go” gray.