What The Hell Is PH And Why Does It Matter In My Skincare?
Seriously though, wtf does pH mean? We get this question a lot and for good reason. Although it looks more like the element on the periodic table you missed on that 8th grade pop quiz than something you want popping up in your skincare, pH, short for potential of hydrogen, is pretty damn important.
Striking the right pH balance is linked increasingly (by science (1, 2, 3, 4)) to healthy, dewy skin. Or, in more clinical terms, linked to a fully functioning acid mantle, healthy skin moisture barrier and a thriving microbiome: the ecosystem of good bacteria (or flora) that keep skin safe. These three things are the major players on your skin’s first line of defense, and are capable of fending off diseases like acne, eczema, psoriasis and dermatitis and their common denominator symptoms like redness, inflammation and irritation. So it follows that skincare products formulated to help maintain your skin’s ideal pH should be a no-brainer, right?
That’s the short version. In the information overload below, we’ll walk through the highs and lows of pH levels, scratch beyond the surface of pH-balanced skincare routines and, hopefully, help you make the decision to throw in the towel on old-school cleansers that might be upsetting your skin’s state of zen.
pH 101: What is it?
pH level describes how concentrated hydrogen ions are in a solution. Put another way, it’s the acid-alkaline ratio of a substance, aka, how acidic something is. pH level is measured on a scale of 1 (highly acidic) to 14 (highly alkaline). Overall, our bodies are more-or-less neutral at 7. But our skin skews more acidic, around a pH of 5.7, to aid in its defense position by creating an environment where skin flora thrive but bad bacteria struggle to survive. Skincare formulas outside of that range can disrupt your skin’s acid mantle by driving its pH level up or down.
OK - but what’s the acid mantle?
The acid mantle is a thin film on the surface of the stratum corneum (the first layer of skin) composed of fatty acids, lactic acid, pyrrolidine carboxylic acid, amino acids....you get it, acids, thus acid mantle. It’s responsibilities bottle down to two main functions:
1) protect skin from bacteria, fungi, pollution, etc., at all costs and
2) maintain the integrity of skin’s moisture barrier and microbiome.
Although pH in skin is still in its early stages of clinical studies, research does demonstrate a clear relationship between a healthy acid mantle and skin flora with a balanced pH level (5, 6). Skin moods like redness, dehydration (which can be simultaneously dry and oily) or inflammation are tell-tell signs of a compromised acid mantle and microbiome, which are often strong indicators that your skin’s pH balance is out of its comfort zone.
And a lot of things can impact your skin’s pH level: pollutants, pathogens, detergents, cleansers, exfoliators — even tap water, or “hard water”, which has a higher pH (8.5 or more) than distilled water. This all might sound like a losing battle for your skin, especially if you’re an urban dweller without immediate access to the world’s purest, straight-from-the-mountain-spring water to splash on your face every day. Thankfully, our skin is incredibly good at changing course, especially with the support of the right topicals. If you think that your tap water is the primary culprit in your skin’s recent mood swing, try using micellar water, developed in France as a direct response to too-harsh water.
pH Then & Now: Why It Matters Matters For Your Skin
Before pH level was a thing in skincare marketing, it was playing an outsized role in skin-unbalancing. Many cleansers of old clocked in at 7 on the pH scale, creating a more alkaline environment for harmful bacteria and leading to increased inflammation, atopic dermatitis or dehydrated skin. That’s why toner — the skin rebalancing OG from the nineties — was formulated: to counter alkaline cleansers and restore disrupted pH levels. Today, toners aren’t super necessary because more and more cleansers are rethinking their pH and staying in the 4-6 range of skin bliss.
But a pH balanced cleanser is absolutely necessary, especially if an exfoliator, vitamin C or any sort of acidic ingredients are a regular part of your skincare routine. Any deviation in the acid mantle — too acidic or too alkaline — throws off the ecosystem of skin by degrading the skin moisture barrier function and microbiome health. When the skin moisture barrier and microbiome struggle, your skin struggles. In sum, pH levels that are too alkaline contribute to drying and dehydration, key components in eczema flares, while on the flip side, too acidic, contributes to increased redness and inflammation.
Putting the pH Back in Your Skin (Care): Restoring Your pH Balance
If you suspect that the pH balance (or lack thereof) of your skin might be playing a role in an angrier-than-usual skin mood, there are several ways you can bring it back to its happy place.
Start with the obvious: throwing out your old cleanser (unless it’s already pH balanced). Be mindful of the rest of your skincare routine, too. Exfoliate sparingly through the week, look for topicals that contain probiotics to help restore a healthy bacterial state, and incorporate replenishing oils like safflower or avocado to help get you skin barrier back on its A-game.
Along with the cleanser itself, how you cleanse is important. A few easy-to-follow rules to implement in your face washing? Don’t overwash — morning and night is plenty. Don’t overscub, or scrub at all unless you’re using a gentle exfoliator a few times a week, max (in which case slow and soft circular motions are the name of the game). Don’t mix and match random products.
How to Layer Products With Different pH: A Summary
It might seem, in theory, like differing levels of pH from one product to another would work to cancel each other out — like the example above of toners, designed to counteract the effects of alkaline cleansers. Although this school of thought isn’t without merit, the execution of your skincare — the how much, how often and how long to wait between products — can make or break its effectiveness. This is especially true of the relationship between common acids like vitamin C, glycolic or lactic and your moisturizer. In general, give your skin at least 20 minutes between exfoliating and moisturizing because those acids in your exfoliator have a greater influence on the pH on moisturizer than your moisturizer has on the pH of acids. So if you don’t give your skin a minute to neutralize the acids, you’re not getting as much balance back from your moisturizer. Your best option, though, is to stick with skincare products designed to work together (on more levels than just pH) to take some of that guesswork out for you.
The Ph.D. of pH: A Working Thesis
Not only does the pH level of skin have far-reaching implications for skin’s acid mantle, moisture barrier and microbiome, but basically anything can have an impact on the pH level of skin. What you’re washing with, sure, but also how often you’re washing and if you’re giving your skin enough time between products to keep that balance on the level. The negative effects of skin pH that’s either too acidic or too alkaline can be reversible by choosing a pH balanced cleanser, using acidic products like exfoliators correctly and being mindful of the pH levels of the ingredients in that home remedy recipe you found on Pinterest. So, if your fave all-natural internet beauty blogger is telling you to use lemon juice (pH level 2) or baking soda (pH level 9) in your homemade cleanser, you might want to rethink that DIY step