Do you know the pH of your shampoo? This is why you should.

Do you know the pH of your shampoo? Why shampoo pH is critical for healthy, shiny hair.

 

Shampoo was my gateway drug into green beauty. Nearly ten (?!) years ago now, I was struggling with hair loss and breakage and began looking into everything and anything that could be contributing to my tress plight. I stumbled upon the hair-damaging effects of sodium lauryl sulfate, and away we went.

The market a decade ago wasn't what it is today, and I wound up deep down a DIY rabbit hole to compensate for the lack of commercial options. There was the time I tried washing my hair with honey (result: unsuccessful), then the experiment of using only water, my fingers, and an apple cider vinegar (ACV) rinse (extreme, I know, but it wasn't as bad as you'd expect). Finally, I ended up trying DIY concoctions with the original green product, Dr. Bronner's Pure-Castile Soap.

I arrived at Dr. Bronner's as an alternative to the most popular DIY shampoo of the time, washing with baking soda and rinsing with ACV (also called the "no 'poo method"), because I knew the No Poo was too harsh for my fine hair. The joke was on me, though, because Dr. Bronner's turned out to be just as bad of a choice. Let's taco bout it.

Clean shampoo? Great! But it better have that low pH.

Though wildly popular, baking soda is a terrible idea for hair cleansing solely because it's basic AF. And by basic, I mean highly alkaline (yuk, yuk). My Dr. Bronner's experiment was a disaster for the same reason. 

"Basic/alkaline" and "acidic" refer to the pH scale, which goes from 0 to 14, with 0 being battery acid and 14 being lye (yikes at both ends), and water, generally, a neutral 7. Our hair and skin are naturally about 4.5-5.5. Baking soda and Dr. Bronner's, on the other hand, are about 9 – way too alkaline for hair and skin to be happy.

Do you know the pH of your shampoo? Why shampoo pH is critical for healthy, shiny hair.

pH poster by brgfx at www.freepik.com

Now, the Internet will tell you that this is an easy solve: You just rinse with something that's highly acidic, like ACV (about a 3.5), and that gets your hair back to the pH that it should be. While this is true, it conveniently skips over the damage done by the alkaline product.

You know how when you stretch a rubber band over and over again and it gets stretched out and crack-y, and ultimately looses its rubber-band-i-ness? That's what a high pH shampoo followed by an acidic rinse does to your hair. The result, as I can attest to, is a texture akin to brittle straw, and hair doesn't fare well. 

The impact of pH on hair

A high pH shampoo destroys hair because of what the basic solution does to the cuticle, the outermost layers of cells of the hair shaft. The cells of a healthy and happy cuticle, which overlap like roofing shingles, lie flat for a smooth and sleek surface that reflects light beautifully (shiny hair). Conversely, a basic solution wreaks havoc by lifting these cells of the cuticle, exposing the interior of the hair shaft and creating a rough surface that makes hair dull, frizzy, and brittle. Following a basic product with an acidic one serves to smooth the cuticle back out again, but it does not repair the damage done. To give a more common example, hair dye and other chemical processes also rely on this mix of basic and acidic: One chemical opens the cuticle, the color is deposited, and then an acidic processor closes the cuticle. Hair emerges pretty, but not healthier.

Some hair is thick and sturdy and can happily handle the rebounding between basic and acidic for lengthy periods of time.  However, those of us with fine and/or curly hair (the curly hair cuticle is naturally more open) can withstand much less before the damage becomes obvious. Again, I wish I didn't know this from personal experience. 

So, all of this is to say, pH is one of the most important things to look for in a shampoo. Find ingredients you like, but make sure the pH will make your hair happy, too! And DIY-ers, seriously beware.

What am I using?

My current hair care is no best-kept-secret. I've been using an assortment of Acure shampoo & conditioner off and on for quite a while now. It's cheap, available all over the place, so easy because it performs like a traditional shampoo, and – most importantly – is both non-toxic and pH balanced. Because it does have surfactants and lathers (I'm not going to go into this now), it is more drying than some of the "no poos" out there, but it does the job and keeps my hair healthy.

You won't find the pH listed anywhere online, but don't worry, I have your back. I tested it with a pH strip (you're welcome), and it's a hair-happy 4.5. Huzzah!  

For extra hair healing, try their Mega Moisturizing Shampoo with Argan Oil & Pumpkin.

The elephant in the (bath)room

Shampoo bars, I see you, and I'm coming for you. I'm working on switching to shampoo and conditioner bars because of the egregious waste of shampoo and conditioner bottles. However, most shampoo bars (with ingredients that live up to my expectations, that is) out there are little more than extra-moisturizing soap, which means they fall into this same pH pitfall. Stay tuned for a deep dive on shampoo bars, coming soon.  

What are your favorite pH balanced shampoos? Are there any hair products you can't live without?

  • lauren's picture
    lauren
  • Hi! I'm Lauren.

    Welcome to the NTB blog, a science-based exploration of information for living our healthiest and happiest lives. I hold a certificate from the University of Washington in Green Chemistry & Sustainability, and believe that living well is doing the best we can in every moment, not doing it perfectly.