Dermatologists Say Hard Water May Damage Your Hair—Here's How to Stop It
Stocksy
Reviewed by Sophia Emmanuel
Hair can appear dull, dehydrated, and frizzy for many reasons. Genetics, lifestyle, diet, and the haircare products we use all play a significant role in our hair's appearance, health, and damage. However, even after considering these underlying factors and taking the necessary steps to care for your specific hair type, hard water could be a hidden enemy responsible for causing damage to your hair.
When we talk about hard or soft water, we’re not talking about its density or feel. "Hard water refers to water with a high mineral content, specifically magnesium, and calcium," says board-certified dermatologist Dr. Marisa Garshick. The more calcium and magnesium the water has, the “harder” it is. You can’t physically see these minerals, but you likely have hard water at home, as about 85% of U.S. households do.
But how do you know if hard water is damaging your hair, and how do you prevent it? And how do you fix damage from hard water already caused to your hair? We asked dermatologists and hair care experts the questions you need to know.
Keep reading to learn how hard water can damage hair and what treatments you can do to counteract it.
Meet the Experts
Dr. Marisa Garshick is a board-certified dermatologist in New York City and an assistant clinical professor of dermatology at Cornell - New York Presbyterian Medical Center.
Dr. Lauren Penzi is a board-certified dermatologist in New York City who specializes in medical and cosmetic dermatology.
Devin Toth is a hairstylist at SalonSCK in New York City.
Bridgette Hill is a certified trichologist and scalp therapist.
What Is Hard Water?
Hard water is water that has an elevated level of dissolved mineral content, with the most common minerals being calcium and magnesium, according to Dr. Garshick.
Is Hard Water Bad for Your Hair?
While hard water is typically not concerning for internal health, Dr. Penzi, a board-certified dermatologist, says with long-term usage, "Hard water [can] cause hair to become more brittle, frizzy, and prone to tangling and breakage. The hair becomes drier, as the hard water buildup prevents the hair from absorbing moisture in products like conditioner."
This build-up of mineral content can have several adverse outcomes for the appearance and health of your hair, including:
Blocking moisture: Mineral residue from hard water clings to your hair as the water evaporates. That gradual build-up of minerals can block moisture absorption, says Dr. Penzi. This blocking of moisture can significantly impact the health and appearance of the hair, as moisture is essential to preventing frizz and dullness and promoting elasticity and shine.
Promotes split ends and breakage: According to Dr. Garshick, when using hard water, "There is a breakdown of the outer protective cuticle that exposes the inner cortex of the hair, causing weak points along the hair shafts that lead to breakage.
Prevents effective cleansing: The minerals found in hard water can make it difficult to form a lather, which can make it difficult to cleanse hair and scalp effectively, explains Dr. Penzi. "In hard water, soap reacts with the calcium to form a soap-scum type residue," she says, noting that the weigh-down feeling users of hard water report comes from a build-up of this "film" on hair.
Makes the scalp itchy: "As a result of the residue that is left behind with hard water, the skin on the scalp can become more easily irritated," Dr. Garshick says, "Because of this, hard water may make the hair and scalp feel dry, which can also lead to itching in the scalp."
Interferes with hair color: Hard water can cause color-treated hair to fade faster. Blonde shades, in particular, also tend to appear brassier over time, Dr. Penzi says.
Can Hard Water Cause Hair Loss?
Hard water is not a direct cause of hair loss, according to Dr. Penzi. "Studies have shown [hard water] does not interfere with hair's elasticity or tensile strength," she says, "Hard water can cause frizziness, dullness, and split ends, which can interfere with the proper growth of hair, but it does not cause your hair to just fall out.
Which Hair Types Are More Prone to Damage?
No hair is truly immune to hard water damage; however, “Hair textures that are highly porous are more susceptible to minerals penetrating deeper into the hair structure, making it more susceptible to hard water [damage],” says trichologist Bridgette Hill. Color-treated and chemically treated hair fall into this category, as well as curly hair types prone to dryness and frizz.
How to Know If You Have Hard Water
If you're trying to figure out whether you have hard water, this is where you’ll need to do a little detective work. But the good news is there are several ways to learn what kind of water you have.
When hard water evaporates, it leaves the minerals behind. If you’re constantly battling a fily, crystallized white or greenish coating on and around your faucets—that’s a good sign that you have hard water, according to Dr. Penzi. Because the minerals in hard water tend to build up and coat pipes and faucets, you may also notice low water pressure in the shower and your sinks.
Your hair could also be a telltale sign. “If your shampoo takes an extra long time to lather or properly distribute, then you may have hard water,” says Toth. “Or if your high-quality conditioner doesn't seem to work and after using it your hair feels dry and tangly—then there's a good chance your hair is being affected by hard water.”
Alternatively, you may already receive an annual water quality report that lets you know your water's mineral levels in what is known as a Consumer Confidence Report. If you do not receive that report, Dr. Garshick says, "There are at-home kits available, but given the potential inaccuracy, the Environmental Protection Agency recommends using a certified lab that can perform the testing."
How to Prevent Damage
So you have hard water. Now what? Well, you can’t help where your water comes from. If you live in an area that sources water from subterranean aquifers, springs, or rivers, it will just naturally have more minerals. But there are a few steps to lessen hard water damage and repair it.
Buy a Filter for Your Shower Head
If you want to mitigate as much damage as possible, start with your shower head. Homeowners can install an entire soft water system in their homes, but it’s expensive and a non-starter for those in apartments. Our experts recommend attaching a water filter to your shower head as a small-scale option, like the AquaBliss High Output Revitalizing Shower Filter ($36). It’s like a Brita for your shower, filtering out minerals like calcium and magnesium—two common culprits when it comes to dry and brittle hair—and should lessen some of the buildup and residue on your strands.
Try a Pre-Shampoo Treatment
“A pre-shampoo hair treatment can create a barrier to assist with minimizing the buildup of minerals that penetrate the hair fiber,” Hill says. Kérastase's Pre-Cleanse Régénérant ($52) is a good choice, as it is formulated with charcoal, hyaluronic acid, and abyssine to help remove existing buildup and promote a balanced scalp before you cleanse with shampoo.
Use a Chelating or Clarifying Shampoo
If you’re working with hard water, Toth recommends looking for chelating shampoo. “[They] contain chelating agents that bind with metals and minerals in water to then be rinsed away,” he says. “It's stronger than a regular shampoo, which would only cleanse away dirt and residue.” When buying a chelating shampoo, Dr. Penzi recommends looking for products labeled as a clarifying or detoxifying shampoo and checking for an ingredient called tetrasodium EDTA or EDTA complex—an effective chelating agent. We love the Ouai Detox Shampoo ($32) because it removes mineral buildup and smoothes hair cuticles, reducing frizz with hydrolyzed keratin. It’s important to note that chelating agents can be irritating if used too frequently, so a shampoo like this would be a great once-a-week product instead of as part of your daily routine.
Related: The 13 Best Shampoos for Hard Water of 2023
The Takeaway
Hard water is caused by high levels of minerals, such as magnesium and calcium, in the water supply. Using hard water to wash your hair can cause hair breakage, frizziness, and dullness, as the mineral buildup from long-term usage can block moisture from penetrating the strands. It can be challenging to avoid using hard water completely since it is present in many locations worldwide. To combat potential damage, experts suggest using a water softener or a shower filter to reduce mineral deposits in the water, and ensuring you properly cleanse your hair and scalp to prevent mineral buildup.
Up Next: Can Hard Water Cause Hair Loss? We Asked Dermatologists
Read the original article on Byrdie.
