Illustration: Matija Medved for Elemental

Is Scalp the New Skin?

The truth about the new class of hair care products

In 2006, Sachajuan, the cult Stockholm hair care brand, debuted a scalp shampoo, expecting it to be a niche product. But in recent years, the shampoo — made with a scalp-tingling peppermint and packaged in an apothecary-like bottle to evoke medicine for hair — has become the brand’s top seller, says co-founder Sacha Mitic. Little wonder, then, that Sachajuan subsequently released a scalp treatment, a scalp conditioner, and, last month, a scalp scrub and scalp brush, the latter of which sold out almost instantly.

“It’s very important to clean the scalp,” says Mitic, who has also been a hairdresser since 1978. “It really affects the health of the hair, and it also gives you a really nice feeling.” The instinct to soothe ourselves via the scalp is hardwired, he suggests: “Look at a baby crying. What is the first thing people do? Calm it on the head.”

Indeed, scalp care products are booming, as beauty companies scramble for practically the last piece of unclaimed territory on the body. (What’s left — behind the ears?) Skin care brands like Drunk Elephant, Dr. Barbara Sturm, and the Inkey List are branching into scalp care with $100 scalp serums and $36 scalp scrubs. It’s also fertile territory for startups: The founders of Jupiter, which launched last year, say they “realized the next frontier in self-care is scalp care for healthy hair.” Headquarters, a new women’s scalp care brand from direct-to-consumer shaving brand Harry’s, debuted in January. One look at the marketing materials for these products and you can practically feel the tingle — no matter how clean your hair is, you may find yourself itching for a shower.

It’s lucky timing for companies, coming just when people want to treat themselves to self-care products. It doesn’t hurt that most scalp treatments, like the one from Sachajuan, include ingredients that produce those tingling or warming sensations, which “give you a perceived enhancement of efficacy,” says Kelly Dobos, a cosmetic chemist. Plus, they feel delicious.

“Viewing the scalp as the soil and the hair as the crop is a really easy analogy to make, but it’s not entirely accurate. We do not need to become master gardeners of the scalp.”

There’s just one catch: Unless you actually have a condition like dandruff, hair loss or thinning, or psoriasis, you probably don’t need a scalp treatment, let alone the complete scalp care regimens many companies are selling. (Never mind that scalp masks, serums, and scrubs can cause problems of their own — or exacerbate existing ones.) And if you do have a genuine scalp problem, before you spend $100 on a “scalp-balancing serum,” it’s probably worth scheduling a dermatologist visit first. The solution is most likely a simple medicated shampoo or a prescription, not anything promising to detox, purify, or “promote hair growth” with exotic ingredients derived from some idyllic-sounding place.

“These companies are telling people they’ve been ignoring their scalp health, and most people are like, ‘That makes sense,’” says Maryanne Makredes Senna, MD, a dermatologist and the director of the Hair Academic Innovation Research Unit (HAIR — get it?) at Massachusetts General Hospital in Boston. “But it’s a cash grab. For the average person, I don’t see a benefit to these products.”

S. Tyler Hollmig, MD, an associate professor of dermatology at Dell Medical School at the University of Texas, agrees, saying most of the claims, like promoting hair growth, don’t even make sense physiologically. “Viewing the scalp as the soil and the hair as the crop is a really easy analogy to make, but it’s not entirely accurate,” he says. “We do not need to become master gardeners of the scalp.”

To understand why not, here’s a bit on how the scalp works. Like the skin on your face, the scalp is its own microbiome, complete with some very necessary bacteria and fungi. The sebaceous glands — there’s one for every hair follicle, up to 6,000 per square inch — secrete natural substances designed to keep things in check.

Here’s where problems start, Senna says. People see their scalp flaking or itching and think, “Oh, it must be dehydrated. I need a scalp treatment.” But dry scalp is actually rare, she says. Unlike your possibly over-washed, over-hand-sanitized hands, your scalp isn’t likely to be crying out for moisture, because it has all those sebaceous glands. Bombard it with products and the flaking will only get worse. Whitney Bowe, MD, a dermatologist in New York, says “the vast majority” of scalp problems she sees in her office “are self-induced” from use or misuse of products.

Instead of dry scalp, the issue is usually either seborrheic dermatitis or scalp psoriasis. “Seb derm,” as dermatologists refer to it, is an overproduction of oil, which the Malassezia yeast that live on the scalp love to feed on, creating flakes. Seb derm can also come about when you have a normal amount of yeast but your immune system overreacts to it. Meanwhile, scalp psoriasis is an autoimmune condition where the body’s skin cells divide too quickly and don’t shed, so they pile up in inflamed, scaly patches.

To be clear, these scalp health issues are real and may even be on the rise. According to data from Google, searches for “scalp,” “dandruff,” and “seborrheic dermatitis” (a fancy way of saying dandruff) are at all-time highs in the United States since 2004, when the company started tracking trends.

“There has to be some sort of intervention, but it’s not a $100 scalp product,” Senna says. Still, the more expensive a product is, the more attached patients are to it, especially if it seems “natural,” she says. “I literally have to talk them into medication, even if it’s covered by prescription.”

Only in more extreme cases, like if you have heaped-up seb derm or thick psoriasis, Senna might recommend a product—sometimes prescription, sometimes over the counter—that is antibacterial and contains salicylic acid simply to remove the scale before medication can reduce the inflammation.

If your problem is inflammation or an oily scalp, there are fixes that don’t require any scalp product. This is when it’s time to consider some chemistry. The scalp has a pH of about five—it’s purposely acidic to prevent overgrowth of bacteria. But lots of leave-in products and shampoos are too alkaline and strip the scalp, irritating it and making it produce too much oil. A Brazilian study analyzed 123 shampoos and found that less than 40% of them had the appropriate pH for scalp; no similar study has been done in the United States, but Senna says she has no reason to think it would be different.

So, before you do anything else, she says, consider buying some pH strips for about $7 on Amazon and test your shampoo. (A handful of skin care brands are beginning to list pH on the packaging, but this transparency hasn’t yet hit hair.)

Of course, there may be no more powerful motivator to buy a lot of scalp products than the fear and distress that can accompany hair loss, something many dermatologists report seeing in record numbers during the pandemic. Stress can shove hair prematurely into the resting state, known as the telogen phase, where it hangs for about two months before it falls out. Telogen effluvium — when you can shed some 60% of your hair — usually occurs at least two months after a triggering event like pregnancy, significant weight loss, a bout of Covid-19, or just trying to survive a global pandemic.

The good (and maybe also bad) news is that people experiencing telogen effluvium don’t need anything but patience: Hair regrows all by itself at a rate of about one centimeter a month, Senna says. This biological fact may also be what contributes to a product’s rave reviews — if you don’t already know the hair will come back, any product you use looks like a miracle. (The only product proven to help hair regrow is minoxidil, aka Rogaine, and it stops working once you stop using it.)

Still tempted? It’s worth keeping in mind that most disorders responsible for hair loss have their root cause in the dermis and subcutis, where the bulk of the hair stem cells are found. These layers are beneath the epidermis, which topical products generally can’t penetrate and therefore have zero effect. Hollmig compares the way these products work to the recent freezing temperatures in Texas. “The surface of Lake Austin froze last week, and yet the lily pads are already popping back up,” he says.

If the only reason you’re buying a scalp treatment is because you like how it feels, that’s legit, Senna says. Just recognize that a bit of relaxation is all you should expect from it, and take all claims with a grain of sugar (the preferred ingredient for scalp scrubs, since salt can damage the pigments in artificial hair color).

Consider: “Scalp-balancing” is a marketing term without any clinical relevance, Dobos says, and there is no agreement about what “anti-aging” actually means for the scalp. Other treatments claim that a clean scalp “promotes hair growth,” but this is true only in that an obviously occluded scalp makes it difficult for hair to grow, Hollmig says. For that, you need really severe irritation, not just a week of feeling too overwhelmed to wash your hair.

When evaluating products — especially pricey ones — it’s worth remembering that ingredients are often chosen with an eye toward the marketing story that can be told about them. For moisturizing, for example, it’s hard to beat good old glycerin, which is about as exciting as industrial white bread. Instead, there is a push for trendy adds like hyaluronic acid, which costs a whopping 1,000 times as much as glycerin, Dobos says, and no, that’s not a typo. Dobos says she has to insist that ingredient manufacturers compare whatever they’re selling to glycerin. “Oftentimes, they don’t want to show you that it’s not any better or not even as good,” she says.

Finally, and as with your face, keep in mind that “natural” and “organic” are not always better, Bowe says. Scalp treatments are often loaded with essential oils and botanical extracts, many of which are known allergens and irritants and cause itching, burning, and flaking. There are too many to list here, but two troublemakers Bowe often sees are peppermint oil (an allergen) and witch hazel, which has a high alcohol content and can be drying.

You probably also want to avoid any leave-in product with CBD. “It’s like the Frank’s Red Hot commercial — they put that shit in everything,” Dobos says. Not only is the CBD that goes into beauty products not standardized — so you have no idea of its potency — but it also contains terpenes, a class of molecules responsible for the “green” smell of things like hemp and a known allergen. Fragrances have to be labeled if they contain terpenes, but cosmetics don’t, because the FDA regulations are different.

If there’s nothing amiss with your scalp, don’t let anyone make you think you need a specialized regimen for it. If you really want to optimize your scalp health, try spacing out your shampoos — keep it to, say, every third day, according to Bowe. This is because shampoos can strip the scalp and hair of natural oils and lipids. (This doesn’t apply to people with dandruff, who benefit from more frequent shampoos.) She also suggests avoiding products that contain harsh surfactants, like laurel sulfates and laureth sulfates, which can be irritating with long-term use. Massage is also great for the scalp — it boosts circulation, delivering amino acids and other nutrients that help the enzymes in the scalp function. But stick to using your fingertips; anything that scratches or scrubs (like a brush) can cause the scalp to release histamine, increasing inflammation. Says Bowe: “Many of these brushes are doing more harm than good.”

Finally, don’t stress about what you’re not doing for your scalp — and try to carve out time for meditation, yoga, or whatever relaxes you. “Stress is definitely linked to hair health and scalp health,” Bowe says. “The mind-skin connection is real.”

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