Umm...Why Does Hair Turn Gray (& Can We Slow Down the Process)?

Have you ever wondered, ‘Why does hair turns gray?’ The simple answer is that it’s a part of the aging process. The slightly more scientific answer is that as your hair follicles (and you) age, they produce less color, so when you go through the natural cycle of shedding and growing new hairs, they’re more likely to come in gray after a certain age, which is typically around 35 for most people.

That said, genetics factor heavily into when this happens, which is why some people start to gray in their twenties, while others won’t notice a significant change in color until their forties. Regardless of exact timing, it’s something that eventually happens to all of us.

To help us better understand why our hair turns gray, we spoke to two experts who are well-versed in all things hair: a dermatologist and a stylist.

• Dr. Rebecca Marcus is a board-certified dermatologist and the founder of Maei MD. 
• Nick Stenson is a professional hairstylist and the founder of Nick Stenson Beauty.

“Hair color is determined by the presence of different types of melanin in hair,” explains Dr. Marcus. “Eumelanin is responsible for dark hair, and when present in high amounts, results in black hair, or in slightly lesser amounts, brown hair. Conversely, blond hair is characterized by an absence of eumelanin, or a very small amount of it,” she says, before noting one more type: pheomelanin, which is responsible for red hair.

“Hair turns gray as we get older and melanin production halts in the follicles,” says Stenson. “As people age, the melanocytes [melanin-forming cells] in your hair follicles become less active and eventually undergo apoptosis, or cell death. As a result, your hair is more likely to grow in without pigment, and be gray,” Marcus further explains. “In addition to this, studies have shown that oxidative stress caused by environmental factors such as UV radiation, pollution and even emotional stress can lead to premature failure of melanocytes within hair follicles.” More simply put, certain kinds of environmental and emotional stress can cause premature graying.

Once a hair grows out of a follicle, it doesn’t change color. “However, as new hair grows from aging follicles, the pigment cells become less active over time and are less likely to produce pigment. This happens gradually, and most often begins after the age of 35,” shares Marcus.

Both experts agree that genetics usually plays the biggest part in the age and rate at which someone begins to gray. “In some cases, a medical condition such as a thyroid disorder, neurofibromatosis, a vitamin B12 deficiency or vitiligo may cause hair to gray prematurely,” says Dr. Marcus. But in most cases, it boils down to your genes, so if you’re curious about when you’ll start to gray, you can look to your parents for some indication.  

According to Stenson, the jury is still out on these types of products. “There are currently no scientific studies, to my knowledge, that prove that supplements affect melanin production and therefore prevent graying hair,” he says.

It is possible that in some cases, particularly if your graying is due to an underlying nutritional deficiency of copper, iron, calcium or zinc, which are all thought to be related to melanogenesis (aka the process by which melanin is produced), taking a supplement could influence the pigmentation of hair. However, you would have to see a doctor and get tests done to determine if you have an actual deficiency in those areas.

As mentioned above, there are no scientifically proven methods that slow down, prevent or reverse graying hairs yet, so maybe hold off on spending any significant money on products that claim to do this.

However, our experts suggest that taking certain vitamins such as D, B12, B9 and B5, along with minerals like iron, calcium or zinc could help, but only if you’re deficient in them. Aside from that, try to keep your stress and UV exposure levels low, which has the bonus effect of keeping your complexion happier, too.

And hey, letting your grays grow in has never been more chic or easier to do (especially with all of the various coloring techniques that help ease the transition).