What is pH, Exactly and Why Does It Matter for Your Shampoo?

Jul 18th 2018

We’ve all heard the term “pH” bandied about over the years. Mostly, it’s been a selling point for everything from deodorant to skin care products and other toiletries and beauty products on commercials. It sounds good, true, but what does it actually MEAN when it comes to the products you use on your hair and skin? Does it matter whether a product is “pH balanced” or not? And if so, then why does it make any kind of difference in the health or appearance of our hair or skin? Related: How Often to Wash - Why Does My Hair Look Bad Between Washes?

pH – a Definition and Quick Chemistry Lesson

I never was very good at chemistry. One thing I do remember is that I found it fascinating that water is a combination of hydrogen and oxygen. These two molecules combine to make the very thing that sustains us daily, even more so than food. Hydrogen forms the basis of so many other elements, and the pH level is a measure of the concentration of hydrogen in any given material. It literally means “Potential of Hydrogen”.

The pH scale measures the acidity or the alkalinity of any given substance. It measures this on a scale of 1-14, 1 being the most acidic, and 14 being the most alkaline (also known as base or basic). Any extreme on this scale is not good for human consumption, since both extreme acidity and extreme alkalinity can cause corrosion to any tissue. This is where the popular phrase “pH balanced” comes in. Since you don’t want anything on the extreme end of the scale, it is thought that having something in between is best to maintain the moisture balance and protective barriers of the skin and hair.

So why is this pH “balance” considered important when it comes to shampoo?

Shampoo is one of the most oft-discussed products when it comes to pH levels. Why some much attention to this particular product over others? Shampoo tends to be on the more base or alkaline levels due to the fact that it requires a lathering or sudsing agent to be the most effective at cleansing the hair and scalp.

These lathering agents, even the organic-approved, sulfate free ones, tend to have a more alkaline makeup. If they are too alkaline, meaning higher than the 7 neutral "baseline" on the pH scale, they can actually cause roughing up and breakage of the protective cuticle that encases the hair strands. It is also theorized that it can result in color loss if you color your hair because it tends to lift the color deposits out of the hair faster. Related: How to Get Your Hair to Dry Faster with Your Hair Dryer

So, what is actually the “ideal” pH for shampoo then? 

The level has been estimated to be between 5 and 7 per most hair care experts and those that know a thing or two about chemistry. This means that the ideal pH for shampoo is actually more on the acidic side than the alkaline side. And why would that be?

Well, it most closely mimics the acidity of the scalp since the sebum that protects and inhabits the scalp is roughly this same pH level. So the theory is, you can cleanse the hair and scalp with the least bit of roughing up or disturbance by using a cleanser that most closely matches the natural acidity of the scalp and hair itself.

It makes sense that something on the more acidic side would be better for the hair. Consider how something highly acid in nature, apple cider vinegar (which incidentally, our shampoo contains), is supposed to be an excellent treatment for hair porosity. Porous hair is often caused by the damage of bleaching and lifting agents and other environmental and product related damage.

Many of the things we put on our hair to straighten it, get it smooth, lighten it, or any other number of manipulations, breaks the cuticle in order to break the hydrogen bonds and get the desired look. Over time, this causes damage, and something very acidic like ACV can come in and smooth things out again. Of course, it must be diluted with water so as to not have too much of an acidic effect, but you get the point.

So to summarize, generally a shampoo should be on a pH level of anywhere from 5-7 on the acid/alkaline scale in order to have the most benefit to both the hair and scalp. Although most brands don’t advertise this, you can often write in to them to get the information, or there are even websites now that gather this information for the consumer and post it. So it’s becoming more of a consideration when it comes to how consumers choose their shampoo. For more information on the pH level of our Natural Shine Enhancing Shampoo, visit our product page.