13 Hair Products That Combat the Effects of Hard Water

If you’ve ever left the beach with crunchy, clumpy, or filmy hair, you have an idea of how hard water buildup feels. Luckily, a hard water hair treatment, like a clarifying shampoo, serum, or rinse, can address that feeling and deeply cleanse and restore your hair in as little as a few uses. 

Whether you’ve never considered the water hardness of your household tap or you’re keenly aware of it, hard water hair damage can show up as an immediate annoyance or possibly pose longer-term problems for your strands. Here’s what you need to know about hard water—and whether you should add a treatment to address its effects to your own hair care routine.

What is hard water—and how can it affect your hair?

Hard water is characterized by its higher mineral content, specifically, calcium, magnesium, and salt, Marisa Garshick, MD, FAAD, board-certified dermatologist and clinical assistant professor of dermatology at Cornell-New York Presbyterian Medical Center, tells SELF. When you wash your hair with hard water, those dissolved minerals can end up accumulating on your hair and scalp, which can prevent your hair from absorbing moisture. This can make it feel “dry, dull, frizzy and unmanageable,” Rebecca Marcus, MD, board-certified dermatologist and founder of Maei MD, tells SELF. Again, think of that crispy, ocean-swept feeling—it may be difficult to comb or brush your hair, and it might not feel as soft as it usually does. Meanwhile, your scalp might feel dry and itchy, Dr. Marcus says.

And, in the long-term, “the buildup can take a toll on the hair, leading to breakage,” Azadeh Shirazi, MD, ​​board-certified dermatologist and owner of La Jolla Laser Derm in La Jolla, California, tells SELF. Every expert we spoke to brought up the increased risk of breakage and brittleness that comes with regularly washing your hair with hard water. 

Mineral buildup can also make it harder for shampoos and other hair care products to perform well. And when you can’t get your shampoo to lather, dissolve, and rinse out thoroughly, it isn’t effectively removing dirt, oil, and hard water residue from your scalp and hair, Dr. Shirazi says. (Talk about a vicious cycle.)

You can also see the effects of hard water on your hair color if you regularly dye it, Lauren Penzi, MD, board-certified dermatologist at Medical Dermatology and Cosmetic Surgery in New York, tells SELF. Color-treated hair, especially hair that’s been dyed blonde, will look brassy and fade more quickly when regularly washed with hard water, she explains. 

What types of hair treatments can address the effects of hard water?

You can start with a clarifying shampoo that contains surfactants (aka cleaning agents). Some products will use sulfates—most commonly sodium lauryl sulfate or sodium laureth sulfate—as their surfactants because they generate a satisfyingly sudsy lather while attracting and rinsing away residue, as SELF has previously reported. That said, some hair care brands avoid sulfates in their formulations because they’re known to be drying for some people (and may even contribute to buildup down the line, depending on your hair type, Dr. Penzi says).