Beauty elicits a deep, instinctive need to share — from an early age. In fact, we defy you to find a more generous creature than a 7-year-old with a sparkly, new lip gloss in her backpack. Cooties be damned, she will prettify every second grader in sight. And we get it: We've built careers on swapping beauty secrets (and, OK, maybe a gloss or two).
We see this same communal spirit, shall we say, within the industry. Across brands and categories, this "borrowing" of ideas and technologies sparks trends and spawns knock-offs. Cosmetic ingredients flow freely, breaking all boundaries: Those once reserved for creams find their way into compacts. The same earthy clay and charcoal that purify pores can also whiten teeth and degrease roots.
And we're all for spreading the love — when the science is legit. But the latest take-over — hair-care companies co-opting buzzy skin-care actives, like peptides, stem cells, and antioxidants — has us questioning just how translatable such technology truly is. Are we going too far in attempting to "revitalize" something that's technically dead?
Meet the experts:
- Randy Schueller is a cosmetic chemist and author based in Illinois.
- Jim Hammer is a cosmetic chemist and the founder of Mix Solutions in Massachusetts.
- Melissa Piliang, MD, a board-certified dermatologist with the Cleveland Clinic in Ohio.
- Ni’Kita Wilson is a cosmetic chemist and vice president of product development at Ouai.
- Ginger King is a cosmetic chemist and founder of Grace Kingdom Beauty.
- Vivian Diller, PhD, is a psychologist based in New York City.
- Rachel Anise is a communication studies professor at Golden West College in Huntington Beach, California.
- Lindsey Bordone, MD, is a board-certified dermatologist in New York City.
- Jeannette Graf, MD, is a board-certified dermatologist in New York City.
- Krupa Koestline is a cosmetic chemist and founder of KKT Consultants.
- Michelle Henry, MD, is a board-certified dermatologist in New York City.
- Nicole Rogers, MD, is a board-certified dermatologist in New Orleans.
- Francesca Fusco, MD, is an assistant clinical professor of dermatology at New York City's Icahn School of Medicine at Mount Sinai.
While skin and hair are composed of similar proteins and fats, living (innervated, blood-perfused) skin cells are in "a constant state of renewal, rising up, plump and fresh, from the basal layer before eventually flattening out and sloughing off," says cosmetic chemist Randy Schueller. When injured or damaged, "skin has the capacity to heal itself through normal biological processes," adds cosmetic chemist Jim Hammer. Hair, on the other hand, is dead — at least the grown-out lengths of which we see and style and twirl.
Hair's only vital part is nestled deep within the scalp: "The cells of the hair follicles reproduce rapidly, pushing out hair fibers in the process," explains Melissa Piliang, MD, a board-certified dermatologist in Ohio. But once sprouted from the scalp, those strands possess no living cells or repair mechanisms.
These distinctions have long dictated product goals: "Skin care aims to affect biological processes, such as boosting cell turnover, increasing collagen synthesis, and inhibiting pigment production," says cosmetic chemist Ni'Kita Wilson. Knowing this, we obsess over penetration — can those actives actually get into the skin to do their good work? — and chemists devise deep-diving delivery systems and penetration enhancers to guarantee performance. "For hair, there really isn't much that can be done on a biological front short of improving the condition of the scalp to promote healthier strands," adds Wilson.
It makes sense, then, that the majority of hair potions are designed to work on the surface, moisturizing and sealing hair to make it glassy, smooth, and full while minimizing friction and breakage. While certain perfectly sized and shaped hydrators and proteins can seep past the hair’s outer cuticle layer, into the deeper cortex, says Wilson, their effect is short-lived. Only chemicals like hair dyes and relaxers can alter hair in a lasting way.
So what of these new skin-inspired #hairgoals we're hearing about, like anti-pollution and high-tech hydration? "Most of this is marketing-driven, with maybe a kernel of truth underneath," says Schueller. That kernel could be a single lab test showing a specific active, when dripped on cells in a glass dish, has some sort of effect — which, by the way, doesn’t mean it will work "when delivered in final products on real people," he notes. Or perhaps a company finds a common water contaminant causes some degree of hair damage — and then concocts an antioxidant to combat it. Even if the trauma to hair is minuscule compared to ordinary wear and tear, "they've now got enough data to make an antipollution claim — and a new line of products to go with it," Schueller says.
Across beauty lines, science sells: "How do you make hair care more innovative? By using skin-care ingredients that elevate the level of sophistication," says cosmetic chemist Ginger King.
It's a successful tactic, judging from the proliferation of skin-inspired shampoos and serums on shelves, real and virtual. But why are we so eager to buy? Our population is aging, of course; "yearning to maintain a healthy appearance, to look as young as we feel," says psychologist and marketing consultant Vivian Diller, PhD. "Any product that promotes youth, well-being, and vitality will be enormously appealing."
According to Rachel Anise, a communication studies professor at Golden West College in Huntington Beach, California, there may also be social-psychology constructs at work here. People, on the whole, are largely swayed by what she calls the halo effect: "We see stem cells, for example, as 'good' at a basic level, and thereby extend their goodness to everything else in which they may be included, even if that reasoning is fundamentally flawed." And then there's the way we process advertising claims, she says, quickly and effortlessly, without thinking critically about them. "Instead of questioning if or why antioxidants may work on hair as they do skin, we'll just see a model with beautiful hair, acknowledge from past experience that antioxidants benefit skin, and automatically make the connection — in two seconds, no less — that they'll give our hair a youthful edge as well," says Anise.
Lucky for you, beauty analysis is sort of our jam. Here, we reality-check three adapted-for-hair-care claims:
The Claim: Slowing down the aging process
WHAT IT MEANS FOR HAIR: "The way hair ages has a lot to do with genetics and overall health," says Lindsey Bordone, MD, a board-certified dermatologist in New York City. Hair tends to become finer over time as follicles miniaturize after menopause, she adds. It may turn coarse and brittle, and as pigment production wanes, fade to gray. On the scalp, cell turnover slows, giving rise to oil and flakes. UV rays — a main cause of skin aging — can degrade hair's proteins and color, "but you'd need a lot of concentrated sun exposure for that to be a real problem," says Schueller.
WHAT WORKS: Collagen and elastin proteins can cling to hair's surface, plumping and softening — but only until your next shampoo. Plant-based stem cells essentially serve as antioxidants, curbing free-radical damage, but their ability to thicken hair (or skin for that matter) is largely unproven.
Surprisingly, peptides, which rev up collagen production, do show promise for aging hair. On the face, they plump skin to delay wrinkles and sagging. When applied to the scalp in a leave-on formula, they aid in "anchoring the follicles to help strands remain firmly planted for a thicker head of hair," says Wilson. According to New York-based board-certified dermatologist Jeannette Graf, MD, "Peptides are especially beneficial for thinning hair, which results from weakened scalp skin and circulation." Alongside peptides, she suggests looking for essential oils of lavender, orange, sage, and lemon peel to "improve microcirculation and enhance the delivery of nutrients to the hair bulb for healthier strands."
As for sun care, hats trump UV filters. "Think about how much sunscreen you need to put on skin to truly protect it," Schueller says. "It's the same for hair and scalp: You'd need a tremendous amount, and who’s going to apply that heavy of a coating?"
Alpha hydroxy acids (AHAs) like glycolic and lactic acids have been popping up in some hair-care products, but while they're often linked to exfoliating away some signs of aging in skin-care products, the same claims can't be made when they're in shampoos and conditioners. "If the AHAs are targeted toward scalp care, it may have some benefits, but more studies are required. Otherwise, it's a bit of that science washing where brands are using ingredients consumers are familiar with but in the wrong context," says cosmetic chemist Krupa Koestline. "For the actual hair cuticle itself, AHAs serve no purpose."
The Claim: Combatting pollution
WHAT IT MEANS FOR HAIR: Every day, our hair, like our skin, is exposed to free radical-inciting pollutants in the air and water. According to New York City-based board-certified dermatologist Michelle Henry, MD, "All types of pollution, including particulate matter, dust, smoke, nickel, lead, and sulfur dioxide and nitrogen dioxide [emitted from vehicles and power plants] can settle on the scalp and hair causing significant inflammation, dryness, dullness, even hair loss."
If that weren't devastating enough, ground-level smog, which contains high levels of ozone, can bleach our hair color, says Hammer. Other contaminants may rob it completely: "Premature graying is seen more in smokers than non-smokers as a result of oxidative stress," says New Orleans-based board-certified dermatologist Nicole Rogers, MD, adding that "free radicals from all sources — not just cigarettes — can affect the follicles' ability to re-pigment."
That said, pollution's precise toll on hair is unknown. "I haven’t seen a ton of research proving it’s a major threat," says Schueller. "Of all the things that can harm hair — chemicals, brushing, heat — I'd imagine free radicals are low on the list."
WHAT WORKS: With thinning and graying as potential consequences, why take chances? While only a diet rich in free radical-quelching antioxidants can truly defend hair at a follicular level, certain products and practices can help safeguard strands from the environment. For starters, "washing your hair thoroughly and with sufficient frequency for your hair type is key to curbing the scalp inflammation that contributes to hair loss," says Dr. Henry. Shampoos with chelating agents, like EDTA, will gently extract heavy metals (found in car exhaust, cigarette smoke, and hard water).
You'll also want to look for leave-ins with concentrated doses of antioxidants (think: vitamins, tea extracts, idebenone, resveratrol) to neutralize free radicals, and strand-coating silicones, proteins, and polymers, which "provide a physical barrier, walling off hair from pollutants," says Hammer.
The Claim: Healing hydration
WHAT IT MEANS FOR HAIR: "With a rich blood supply and an abundance of oil glands, the scalp is an extension of our skin," says Francesca Fusco, MD, assistant clinical professor of dermatology at New York City's Icahn School of Medicine at Mount Sinai. It shares the same lipids and humectants, and it's equally prone to dryness and irritation. Hair suffers from dehydration, too, particularly when its cuticle is eroded (by water, heat, and chemicals).
WHAT WORKS: Hyaluronic acid, a water-binding humectant, and ceramides, moisture-retaining lipids, are both found naturally in the skin (and in countless creams and serums). Since they improve the functioning of skin cells, making them more resilient and efficient, both can help keep the scalp in peak condition. When applied to hair (again, leave-on products work best), "they coat strands to lock in moisture while also shielding from heat and styling damage," says Dr. Rogers, noting a 2002 study in which ceramides were shown to bind to African hair, helping to reduce breakage. Coconut oil and panthenol (a B vitamin) also nourish the scalp, and unlike most other ingredients, can penetrate inside the hair shaft, hydrating from within to enhance pliability, and keeping the cuticle tight and intact.
The Bottom Line
The secret to beautiful hair is a healthy scalp. "When the scalp is out of whack — meaning there's poor circulation, an oil imbalance, or a build-up of cells — we see not only flakes and inflammation, but hair that looks and feels unhealthy, and may even shed before its time," says Dr. Fusco.
Seek out proven actives that take aim at the scalp (many of which do hail from the skin realm): dandruff-fighting pyrithione zinc, clays that absorb excess oil and calm irritation, exfoliating salicylic acid or willow bark extract (which keep cells shedding at a normal clip to prevent pile-ups), and the aforementioned hydrators to soothe and replenish dry, depleted follicles.