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Does the pH Level of Your Hair Matter?

This post was written by Mary Honkus and originally appeared on MAKEUP.COM by L'Oréal.

Back in high school, you probably learned about pH — the 14 point scale that determines whether something is acidic or basic. While you may think that the scale is only useful in science class, pH plays an important role in the health of your skin and hair. “When it comes to hair, pH has a real impact on the bonds and proteins that make up each strand,” explains Boris Oak, founder of EVOLVh Hair Care. Below he explains more about the natural pH of hair, what can happen if the balance is thrown off and how to protect it from damage.


Let’s start with a little science refresher: The pH scale runs from one to 14 — anything that falls between one and seven on the scale is considered acidic, while anything above seven is considered alkaline (aka basic). According to Oak, the natural pH of hair is on the acidic side, usually clocking in at 3.7 on the scale, and it remains at that level for the most part. “pH really comes into play when something comes in contact with your hair,” he says. “Then the pH of that substance will impact the pH of the hair.”


The answer to this question is pretty wide-ranging. Anything that comes into contact with your hair — from products to water and sweat — can change the pH level of your hair. The more alkaline a substance is, though, the more likely it is to damage your hair cuticles. “When alkaline hits your hair, the cuticles are raised which can create all sorts of potential problems,” says Oak. “It can cause hair to become more brittle, more likely to frizz and break, and cause more tangles.”

Unfortunately, it’s nearly impossible to avoid alkaline substances coming in contact with your hair — one of the most common is municipal water (aka what comes out of your shower head). The good news is that once your hair is dry, it will automatically return to its natural pH. “Hair is generally most vulnerable when it's wet because the alkaline water temporarily breaks the bonds that hold the proteins together,” explains Oak. “You don't really have to do anything, per se, to get it to go back to normal, but the damage may be already done.”


The key to minimizing the damage brought on by alkaline substances is using hair products that are pH-balanced in and out of the shower. Start with a [pH-balanced] shampoo. Then, follow up with the EVOLVh SmartStart Leave-In Conditioner [or one of their other leave-ins] post-shower while your hair is still wet. Just a spritz helps to quickly rebalance the cuticles to prevent damage — plus, it provides extra shine, hydration and heat protection.

Be sure to avoid using baby shampoos because they are actually formulated to be more alkaline. “The whole no-tear concept is based around the product not being acidic,” says Oak. “So they don't sting, but they’re really bad for your hair.”

You can also install a pH-balancing shower head to filter out the alkalinity in the water and prevent further damage. We like the Invigorated Water pH REJUVENATE Shower Head Filter because on top of filtering out things like chlorine it also helps to improve water pressure and reduces the amount of water used by 35%.

Photography: Chaunte Vaughn, Associate Creative Director: Melissa San Vicente-Landestoy,  Art Director: Hannah Packer, Associate Creative Producer: Becca Solovay, Associate Content Director: Sarah Ferguson, Makeup Artist: Jonet Williamson, Hair Stylist: Akihisa Yamaguchi, Wardrobe Stylist: Alexis Badiyi, Digital Tech: Paul Yem, Photo Assistant: Sam Kang, Model: Anna