All The Science You Need To Know About Your Skin’s pH Level

I have been having THE WORST breakout lately. What bothers me isn’t so much that it’s been all over my face — although lately it has — but that it’s lasted for such a long time, and no matter what I did, I couldn’t get rid of it.

When I stopped shampooing my hair, I tried to switch over to all-natural body care products, too. The gist of my no-poo conviction is this: Soap-based shampoos strip the natural oils out of your hair and replace them with chemical gunk to artificially make your hair smooth. I get way more volume out of washing my hair with baking soda and lemon juice, and if it’s a little dry, I put a little oil in it. (I need to come back to this point toward the end of the post, though, because there’s some science here that I’ve been neglecting for the last six months.)

The thing is that the same exact idea applies to facial cleansers, even “all-natural” cleansers. The reason soap-based, chemical products strip the oil away from your hair or skin or whatever is that they’re extremely alkaline and they act as surfactants.

Don’t worry, I’ll explain: “Alkaline” has to do with the pH scale, which you might remember from middle school science class (you know, those little pink strips that turn red or blue). Substances that mix chemically with water can be alkaline or acidic. When water mixes with acidic substances, the acidic substances shed hydrogen ions (therefore, they’re drying). When water mixes with alkaline substances, they accept hydrogen ions. That sounds great, except with you’re using a highly alkaline substance like soap, because it causes whatever you’re using it on to be dissolved in water and washed away. That’s how soap acts as a surfactant, which is a substance that lowers the surface tension between liquids and other liquids or liquids and solids. Soap lowers the surface tension between the water you use to wash yourself, and the oils and dirt on your body.

The problem is that your skin has a thin protective layer called the acid mantle that’s made up of amino and lactic acids that mix with fatty acids from the sebaceous glands, which secrete oil that protects your skin. The sebaceous glands are concentrated most highly on the face and scalp, where the skin is delicate and exposed. When you wash your hair and face with soaps, you wash away both the dirt that’s clogging your pores your making your hair gross, and you’re washing away the oil that protects it. So, gaaaack! You have no more natural protection for your skin. It gets dry, which leaves it more vulnerable to the stuff that makes you break out in the first place.

And voilà, you’re stuck in the consumer cycle that feeds the beauty industry: You have to keep using expensive cleansers in order to constantly clear out your pores, but those cleansers keep making your pores vulnerable, so then you also have to buy moisturizers and creams and all sorts of stuff and it’s a vicious thing that you’re trapped in.

Don’t worry, there are solutions! The main thing is this: The pH level of the acid mantle on your skin is about 5.5, or slightly acidic (the pH scale is 1-14, with 7 being neutral, 1 being acidic, and 14 being alkaline). Ditch your alkaline products and find products that are, like your acid mantle, only slightly acidic.

The first step is to ditch cleansers entirely. Shocking, I know; I was surprised, too. Many people swear by the oil cleansing method, which is what I’ve been doing. The science behind it is this: First of all, oil has no pH level, because it’s insoluble in water (without a surfactant). because of that, it won’t affect the pH level of your skin. The fact that it’s insoluble in water is why it makes for a good cleanser – oil is lipophilic; or, in other words, oil dissolves in oil. When you use an oil like grapeseed or jojoba to cleanse your face, you dislodge the dirt that clogs your pores and wipe it away without removing the sebum from your sebaceous glands and the acid mantle that protect your skin.

The second step is to get really comfy and cozy and friendly with toner. Toner is, like the acid mantle, slightly acidic — or it should be, anyway. When I was younger, my sister swore by witch hazel as a toner, and it turns out that witch hazel is the basis of most toners on the market. It has a pH of 3, but a 1:1 solution of witch hazel and water would have a pH of 5. The toner I’ve picked up is from Weleda, which has very-to-moderately acidic witch hazel, lemon juice, and rosehip extract mixed with neutral water and slightly alkaline alcohol as well as non-pH essential oils. Another good one is from Dr. Hauschka, but honestly, I don’t have that kind of money. It smells like heaven and you can spray it on over your makeup, though, which is a big draw. The benefit of using toner many many times a day is that it cleanses your face while supporting its pH balance.

The third step is to get into a routine for cleansing, toning, and moisturizing. You should only cleans in the morning when you wake up, and to get your makeup off in the afternoon or evening. If you do it more than that, the wiping can dry out your skin. Tone several times a day, and moisturize afterward, but not at night, so that your skin can breathe.

The fourth step is to eat well, which you probably already know to do. But it’s worth considering the possibility that alkalizing foods like fruits, vegetables, raw nuts, and soy could help your skin at least by providing your body with a ton of nutrients (the science on the idea that they actually maintain the pH level of your blood is pretty meh).

And finally, the part that breaks my heart: If you’ve used baking soda for shampoo, stop. Baking soda is extremely alkaline (its pH level is 10) and even when you dissolve it in water, it stays extremely alkaline. You get the benefit of avoiding the gross chemicals that are in shampoo, but you will dry out your hair. Never fear! There is an alternative: You can use rye flour instead. The pH of a rye flour solution is 5, which is just about perfect, plus it contains other minerals that are awesome for your hair. And here’s some great news: A 5-pound bag of rye flour costs about $35, but it’s good for around 95 washes. If you only wash your hair once or twice a week, like I do, that’s a year and a half to two years of showers for $35. Try and tell me you spend less than that on shampoo.

So there you go! Now you have all the science you need to understand why your skin feels crummy. Obviously, this applies to people who don’t have allergies to the ingredients in the products mentioned, and who don’t have special skin problems. My main thing is this: Even if you don’t buy into natural products for body care, make sure you ask your doctor to explain to you in layman’s terms exactly what the products they prescribe for you do to and for your skin. It’s worth not being in the dark. And always, always — wear sunscreen!

[Science Buddies]
[Skincare Rx]
[Oil Cleansing Method]
[Weleda]
[Dr. Hauschka]
[Greenopedia]
[Kanelstrand (1)]
[Kanelstrand (2)]

Follow me on Twitter.