Gray Hair's Science and 4 Fun Facts

Some of us pluck ‘em. Some cover them with a hat. Some spend countless hours in a salon chair getting them covered up, while others wear them proudly. But over a certain age, most of us have them: gray hairs. Whether you love them or hate them, gray hair is scientifically fascinating.

Gray hair is mostly inevitable. Few are immune. With age, hair follicles stop producing melanin, which leads to the production of colorless (gray) hair. While some say it’s beautiful, gray hair can be stubborn and resistant to chemical processes, like those associated with perms and color.

Lack of Melanin Causes Gray Hair

Hair grows out from the root, which is anchored firmly into a shaft in the skin called a hair follicle. Magical things happen in the follicle. In addition to creating keratin cells for hair growth, the follicle possesses melanocytes. These tiny cells are responsible for infusing melanin (color pigment) into the hair shaft as it grows.

Over time, hair follicles lose their ability to produce melanin through processes that are not yet understood. When this occurs, the hair turns gray. Interestingly, it is possible for a hair to be colored on the ends but gray at the roots. It’s also possible for a hair to be banded (alternating sections of gray and pigmented hair) as melanin production halts and starts. Researchers have even found that follicles can begin producing color again after quite some time has passed.

Gray Hair Is Colorless

Silver, white and gray hair aren’t actually that different. It turns out that these all have one thing in common: they are technically transparent. They possess very little amounts of pigment and some, like white hair, possess no pigment whatsoever. If you were to look through each strand under the microscope, you would see through them. So, what makes gray hair look different from one person to the next? Variations in light reflection caused by the diameter, texture and condition of the hair — oh, and trace amounts of pigment.  

Gray Hair Is Stubborn?

Gray hair can be stubborn and difficult to style but not because the structure of your hair changes as it turns gray, it doesn’t really. But gray hair typically shows up when you’re older, when your scalp doesn’t produce as many hair-softening oils — so it tends to be drier and less pliant and that can make it difficult for these strands to take a curl or hold onto styles in the same way that softer locks do.Gray Hair Is Resistant to Chemicals

The outermost, protective layer of hair, the cuticle, is tighter and smoother in gray hair (again only because it’s drier), which can make it resistant to chemical processes. Why? Both dying and curling (perming) processes use chemicals to lift the cuticle, which allows chemicals or color pigment to enter the hair shaft. Gray (drier) hair resists this process, so it can take longer for perms and color to take on these gray, resistant hairs. Fortunately, stylists plan for this and formulate the chemicals accordingly or pre-soften the hair by lifting the cuticle a little beforehand.

While some people turn gray before others, it’s probably an inevitable part of the aging process for most of us. Will there ever be a cure for graying? Maybe! Scientists are busy at work trying to do just that.