There’s some evidence that certain types of tap water can affect your skin and hair, but before we get into that, I have to wonder why you’re asking this question now. Maybe you’re a regular at Erewhon, the bougie bodega for health nuts that’s now selling Jolie’s $148 Filtered Showerhead for “better skin, hair, and wellbeing”? Or perhaps you heard the rumor that French women don’t let tap touch their faces? Or that some celebrities wash their hair and skin with bottled water? Regardless of the reason you ask, the answer is the same: It all depends on what’s in your water, and that usually depends on where you live.
In some cities, “tap water may contain minerals, oxidizers, calcium, magnesium, silica, and iron that can leave residue on the skin and hair, removing natural oils and causing buildup, dryness, and irritation,” says board-certified dermatologist Dendy Engelman, MD. But in general, you’re more likely to have issues if you live somewhere with hard water, which means the calcium or magnesium levels are above 7 GPG (grains per gallon). Testing is the best way to determine your water’s hardness (you can use simple strips or buy a fancy kit, like the one from Tap Score, for a full lab workup). You can also contact your local water to get the average tap-water stats for your area, or use one of the zip-code databases created by companies selling water filters. (FYI: New York City’s water isn’t that bad: On average, the hardness measures 1.8 GPG, but some neighborhoods can be as high as 7 GPG.)
Hard water can be problematic for your skin because it leaves behind dissolved minerals that may cause irritation. It can also interact with your cleanser or soap, creating a film that compromises your skin barrier and interferes with oil production, according to board-certified dermatologist Sheila Farhang, MD. The most common skin issue caused by this reaction is dryness, or xerosis. “I live in Arizona, which is known to have a higher concentration of hard water — that, in addition to the dry climate, has really wreaked havoc on my skin,” says Farhang. Hard water is also known to exacerbate skin conditions such as acne, psoriasis, and eczema, she says. But if you don’t have dry skin or any of those issues, then tap water shouldn’t be a problem for you.
Your hair is another story. Engelman says the minerals in hard water can interfere with natural oils on the hair and scalp, causing hair to become dry, brittle, and more prone to breakage. And if you color your hair, it’s not just hard water you have to watch out for. Some water comes through copper pipes, which can leave behind trace amounts of the metal that affect the color of your hair over time, says chemist Trefor Evans, the director of research at TRI Princeton, a hair-testing and consulting firm. Tap water may also contain chloramines or chlorine; some public water systems use these chemicals to disinfect their water, and if the levels are high enough, they “can dull or remove your hair color, or even change the color entirely,” says Engelman. So if you have a dry scalp or dry or color-treated hair, definitely test your water for chlorine and metals (the Tap Score kit includes these tests).
If you live somewhere with hard water or excessive chlorine or metals, you may want to reconsider washing your skin and hair with tap water. Sure, you could use bottled water, like this skinfluencer, but most people opt for some type of filtration system instead. Just make sure you choose one that treats the particular contaminant or issue you have. Many shower filters, like the one from Jolie, remove chlorine and some metals but don’t address hard water, while some household water-softening systems tackle that hard-water issue but aren’t designed to remove chlorine or metals.
And now that I’ve passed along those tips from the experts, there is one more thing I’d suggest (and if it sounds familiar, that’s because it’s come up before in “Ask a Beauty Editor” columns about Botox, ice facials, and dermarolling): If you’re generally happy with the way you look and feel, and your skin and hair seem healthy, then don’t go looking for unnecessary problems to solve. Because I guarantee if you go to Erewhon — or Sephora, or Credo, or Ulta Beauty — you’ll find a solution to a problem you didn’t even know you had. And that is definitely not a good thing.
Jennifer Sullivan answers all your beauty-related questions with practical advice and zero judgment. Send your questions to AskABeautyEditor@nymag.com. (By emailing, you agree to the terms here.)
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