Can These New Hair Serums Actually Delay Grays?

Amy Eisinger
·11 min read

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Aging is a privilege, but not everyone feels blessed to receive the gray hair that comes with it. About 74% of us will see our first silver strands pop up between the ages of 45 and 65, though many see their first grays pop up as young as their 20s or even in their teens. Gray hair is a normal, inevitable part of everyone’s life, but the first instinct for many people who catch a glimpse of gray in the mirror is to book a color appointment—or look for a more permanent way to hold onto their old shade.

For decades, scientists have been studying ways to slow hair’s aging process. A major 2009 study revealed why hair goes gray in the first place (turns out hydrogen peroxide buildup is to blame). Three years later, a L'Oreal researcher said the beauty behemoth was working to develop a pill that could return hair to its natural color by making pigment-producing cells called melanocytes.

Over 10 years later, we're still waiting for that pill, but we are now being offered new topical formulas that claim they can delay the arrival of gray hair—or even reverse it in its early stages. The hero ingredient in these products is called palmitoyl tetrapeptide-20 amide, and a few small studies have found it to be promising.

There’s nothing wrong with going gray (in fact, we think it looks pretty cool) but, for those who prefer the hair color they used to have, we get the appeal of a product that could potentially save the time and money spent on regular dye jobs. Do any of them actually live up to their promises, though? Here, we got answers from independent experts.

Meet the experts:

  • Rebecca Marcus, MD, is a board-certified dermatologist and founder of Maei MD, based in Dallas.

  • Hadley King, MD, is a board-certified dermatologist based in New York City.

  • Robert Finney, MD, is a board-certified dermatologist and founder of Soho Skin and Hair Restoration in New York City

  • James O’Sullivan, Ph.D., is a postdoctoral research associate in developmental biology and cell metabolism.

  • Ralf Paus, MD, is a research professor of dermatology at the University of Miami.

  • Alex Padgett is a cosmetic chemist and co-founder of Educated Mess.

In this story:

Why does hair go gray?

Simply put: A loss of melanin—the pigment that colors hair, eyes, and skin—at the root of each hair follicle is what makes hair turn gray. But it’s a little more complicated than a simple deficiency.

The color of our hair is created by the pigment-producing cells, called melanocytes, located in each hair follicle. In the process of generating the pigment for our hair, these cells also produce some other chemicals, one of which is hydrogen peroxide (yes, the stuff that bleaches your hair). When we're young, our bodies also produce enzymes to neutralize that hydrogen peroxide and other free radicals so our hair keeps growing in with color. As we age, however, those neutralizing enzymes become less active than they once were, which means that hydrogen peroxide starts to build up and sap color from our hair, leaving it a lovely shade of gray—and, eventually, white, once the strand has lost all its pigment.

Although most gray is related to a natural part of the aging process, a significant environmental factor is UV exposure, which can accelerate hair aging. One study—on mice, not humans—demonstrated that not only did UV exposure produce gray hairs, but it also decreased the diameter of the hairs and shortened the shafts of the roots. To be more specific, exposure to UVA rays (those longer wavelengths) damages hair pigment, while UVB exposure (shorter wavelengths) damages hair proteins, specifically keratin. So sunlight, which carries both UVA and UVB, is a double-whammy for hair damage.

In addition to UV exposure, other lifestyle factors contribute to going gray, like smoking, anemia, poor nutrition, low B vitamins, and untreated thyroid conditions, says Hadley King, MD, a dermatologist based in New York City. Genetics can also play a role; if your parents went gray at a younger age, you probably will too.

One contributing factor that might be a bit more in our control is stress. Scientists found that the body’s “fight or flight” response can contribute to turning hair gray. Remember those pigment-producing cells, the melanocytes? When you're under stress, you release a hormone called norepinephrine, which basically causes your body to go into overdrive—and burn through stem cells at a much faster rate. This means that, as your hair's pigment-producing melanocytes die off (they typically live about 3 to 5 years), there aren't enough active stem cells to replace them all… and some hair starts to grow in without pigment, i.e. turn gray.

Is reversing gray hair possible?

Maybe, especially if you’ve just discovered your first strands of silver. “We know that during periods of stress, individual hairs on your head can go gray. And then they'll turn back once the stressor is removed,” says James O’Sullivan, Ph.D., a postdoctoral research associate in developmental biology and cell metabolism, who has been involved in research on the topic.

A small 2021 study suggests that, at least when it comes to stress-related changes, “there is a window of opportunity during which graying is probably much more reversible than had been thought for a long time,” Ralf Paus, MD, a dermatologist at the University of Miami and study co-author, told Scientific American at the time. If your hair has hit that white stage—when all the pigment is fully gone—science is pretty much in agreement: There's no going back.

When it comes to reversing gray hair not related to stress, research is limited. While some experts we spoke with expressed optimism, others were more skeptical, especially in relation to these newly-trending topical treatments. “If you're applying something topically, like in a shampoo, it's much harder than you think for that to penetrate through to the skin, right down to the root of the hair, where it needs to be,” says Dr. O’Sullivan. “So there's a bit of a dilemma about delivery, and how to get stuff all the way down there.” Studies have shown time and time again how difficult it is for topical products to reach the dermis, where the hair follicles' melanocytes are located.

The dermatologists we spoke with agreed—the success of a hair serum is determined by its ability to get to the base of the hair follicle. “The depth of penetration depends on the molecular size and weight of the active ingredient,” explains Rebecca Marcus, MD, a dermatologist based in Dallas.

If it can get where it needs to go, one topical ingredient that's turning up in a few new products does show promise in reversing gray hair: “Palmitoyl tetrapeptide-20 amide is part of a complex that has been shown to help boost melanin synthesis in the follicle to improve the amount of pigmented compounds being produced,” says cosmetic chemist Alex Padgett.

Still, says Robert Finney, MD, a dermatologist and founder of Soho Skin and Hair Restoration in New York City, studies on this relatively new ingredient are limited—and its ability to make substantial changes to someone’s hair is “yet to be determined.”

Many of the experts we spoke with emphasized that one of the best ways to “delay” gray is actually by adopting a healthy lifestyle. Think: A diet high in antioxidants, getting a good amount of sleep, minimizing stress, and not smoking.

Is there a product available today—other than dye—that can reduce grays?

We’re giving you another big maybe here. (Sorry.) Despite the increasing number of products that claim to reverse gray hair, there are currently no double-blind placebo-controlled studies—the gold standard in clinical trials—showing that they can.

Arey is a company dedicated entirely to slowing the graying process—the brand's serum, shampoo, and scalp scrub all contain palmitoyl tetrapeptide-20 amide—but they want to be clear about expectations. “The idea here is preserving pigment,” says Jay Small, co-founder of Arey. “People think, ‘Oh, I have a whole head of gray hair, it's gonna go black next month’—no.” In the same way that some people may choose to use face creams in conjunction with Botox for optimal results, Small says, some people may need to use Arey in combination with hair color.

To back up its claims, Arey cites two studies that were done on palmitoyl tetrapeptide-20 amide. The first is a 2018 clinical study performed on 15 men that showed an increase in the hair's melanin production in more than 50% of the subjects after they applied a lotion that contained palmitoyl tetrapeptide-20 every day for three months. The second is a consumer perception study done on 104 participants (61 women and 43 men, ages 21 to 70) in which volunteers applied a serum that contained palmitoyl tetrapeptide-20 amide once a day. After a month, 31% of volunteers said they saw less gray hair; 64% reported fewer grays after three months of daily use. These studies were not done on the Arey's specific formulas, but the brand hinted that they'll have their own double-blind placebo-controlled study results to share later this year.

Arey To The Root Serum

$55.00, Arey

Hey Hair Root Revival Advanced Anti-Gray Hair Serum

$130.00, Hey Hair

Other products that contain palmitoyl tetrapeptide-20 amide are HeyHair Advanced Anti-Gray Hair Serum (which claims to reduce gray by about 30% in just three months), Vegamour Gro-Ageless Anti-Gray Hair Serum (64% of participants in their consumer study saw less gray hair in about three months), and Leonor Greyl Serum Énergisant (which has claims that focus on thinning more than grays).

There are also new formulas powered by antioxidants, like the Living Proof Scalp Care Density Serum, made with N-Acetyl-Tyrosine, an amino acid. Living Proof cites an in-house trial led by Ron McLaughlin, their senior vice president of research and development, that was done on 30 people over a 90-day period in which 100% of participants saw an increase in hair thickness (individual hair fiber counts were evaluated in a designated area on the scalp) and over 75% saw a reduction in grays (based on the quantification of visible grays and consumers' perceptions). The trial is promising but was small—and there was no comparison to a placebo or other product.

Vegamour Gro Ageless Anti-Gray Hair Serum

$78.00, Vegamour

Leonor Greyl Serum Énergisant

$120.00, Dermstore

Living Proof Scalp Care Density Serum

$64.00, Ulta

“We can make hypotheses about penetration and efficacy based on chemical structure, but we need real-world, high-quality data before we can know if something like this is effective and safe,” says Dr. King, who wants to see more clinical trials on these products. "There's not enough data for palmitoyl tetrapeptide-20 amide yet to really be able to say [how effective it will be]."

Dr. Marcus was cautiously optimistic about palmitoyl tetrapeptide-20 amide. "Although I do not routinely recommend these products to my patients, if someone is particularly concerned about delaying the onset of graying hair, I do think they would be worth a try,” she says. But she also noted there have been few studies so far—and their findings haven't been consistent. One study, for example, found that while participants reported seeing a reduction of grays in their own hair, clinical examiners reported “no modification in graying” after six months of daily topical treatment with palmitoyl tetrapeptide-20.

After reviewing the ingredient lists of these products, Padgett saw the potential for modest benefits—if you use the products early and continuously. “These products could have the potential to be effective, provided that the ingredient [palmitoyl tetrapeptide-20] is used at the proper level,” she says.

Dr. Finney reiterated that the longer your hair has been going gray, the less likely you will be to able to change it back. “With time, the melanocytes die off, and depending on how long it’s been, nothing is going to wake them back up,” he says.

So if you already have a full head of gray hair, you may not see a dramatic change or any change at all—but perhaps that’s a silver lining.

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Originally Appeared on Allure