In high-school chemistry class, you most likely learned about pH and dipped little, color-changing strips into liquids to see where they fell on a scale of 1 to 14. In case you need a refresher: “Anything below 7 is acidic, above 7 is alkaline, and 7 is neutral, like water,” explains cosmetic chemist Ginger King. Few skincare topics have become as mired in confusion and worry as pH. How can two little letters have such an impact on our skin? As it turns out, how pH relates to our skin and the products we use is fascinating.
The pH of your favorite cleanser, toner, and moisturizer affects your skin, whether you realize it or not. And chances are, it’s not for the better. And despite the worry, finding a pH-balanced skincare is easier than you might think. We’ll put your mind at ease about using skincare products with different pH levels so you can get through your routine faster.n
First thing first: Let’s break down what all this science-y stuff actually means. In case you don’t remember from high school—which, I’m going, to be honest, I definitely needed a refresher—the pH scale runs from 0 (acidic) to 14 (basic). Healthy skin has a natural pH level of between 4 and 5.5, so your skin operates on the slightly acidic side of things and the goal is to use products that will help keep it that way.
That’s exactly why so many key ingredients and actives are acids. Need to moisturize? Slather on hyaluronic acid. Want to brighten? Get to work with the L-ascorbic acid. Feeling like you want to resurface skin? Try an alpha-hydroxy or beta-hydroxy acid. That retinol? Yep, it’s retinoic acid. And the list goes on and on (and on).
What Is pH?
‘pH’ is short for ‘potential to free hydrogen ions’ and is a measure of how acid or alkaline any aqueous solution is. Applied to your health, it’s basically a measure of how much oxygen is in your blood. The higher a liquid’s pH, the more acidic and oxygen-deprived it becomes, with fewer free hydrogen ions available; the lower its pH, the freer hydrogen ions it has.
The pH scale ranges from (0.0-14.0). A pH of 7.0 is considered neutral. Anything below 7 is considered acidic and anything above 7.0, alkaline. The pH of the skin is slightly more acidic and should sit at around (4.5 – 5.5).
Acidity plays a key role in your skin by inhibiting the growth of harmful bacteria and activating certain enzymes in your stratum corneum. When the skin’s pH sits in a normal range, it stimulates the production and secretion of healthy lipids and natural oils that allow the skin to repair and heal itself and stay in a balanced state. The natural shedding process that occurs can be disturbed if the pH is not correctly maintained.
Examples Of pH
- Lemon Juice 2.0
- Vinegar 3.0
- Stomach Acid 1.5 – 3.5
- Water 7.0
- Blood 7.35 – 7.45
- Baking Soda 8.0
- Soap 8.0-11.0
- Ammonia 12.0
- Drain & Oven Cleaner 13.0 – 14.0
The skin is made up of various layers. The outer most layer, the stratum corneum is the protective barrier from the external environment. Sweat and sebum (lipids) sit on the surface of the skin creating an important physical and chemical barrier known as the acid mantle. It’s basically your skin’s first line of defense. If your acid mantle is disrupted the skin becomes more permeable and susceptible to bacteria, chemicals, pollutants, and other microorganisms. Once the barrier is impaired it becomes challenging to keep the skin hydrated and for it to repair itself. From first-hand experience, this is one of the worst-case scenarios because nothing you do seems to help.
The pH of skincare products is super important. A pH difference of 1 may not seem like a big deal, but the pH scale is logarithmic, not linear, and works on 1 to the power of 10.
To Understand The Significance Of The Scale:
- A pH of 5.0 is 10x more acidic than a pH of 4.0
- A pH of 5.0 is 10x more acidic than a pH of 4.0
- A pH of 3.0 is 100x more acidic than and a pH of 5.0
- A pH of 2.0 is 1000x more acidic than a pH of 5.0
Products that are high in alkalinity can dilate and cause swelling of your skin follicles and increase the permeability of your skin. Changing the pH on a continual basis and repetitive use of products that aren’t pH balanced can create problems.
Emulsifiers found in moisturizers and cleansers tend to have a higher pH. Their alkalinity can disrupt the skin’s acid mantle. Extreme pH levels can cause inflammation, irritation, dryness and skin conditions such as acne, rosacea, and redness.
Ideally, the products you are using should stay within the pH range of the skin and sit around (4.5 – 6.0) Products you use regularly and leave on your face should be pH balanced accordingly and sit around the (4.0 – 5.5) range.
A couple of exceptions would be an exfoliating product that contains alpha-hydroxy acids (AHA’s) that are used to create an acidic environment to assist with desquamation (shedding) of the skin. Another would be a professional treatment like a chemical peel that’s designed to neutralize the acidity of the skin.
You can test the pH of products using pH litmus strips from a pharmacy or if you want to get techy, invest in a simple pH meter. If the pH of a product is less than 4 or more than 6 then you should discontinue using it. You can also test your makeup as well.
Because soap is high in alkalinity (8.0-11.0) you should never use it on your face unless it’s specifically pH balanced and labeled as such.
Different pH And Their Affects On Our Skin:
High pH (8 to 14)
Skin-care products with a high pH level (also known as alkaline) pose the biggest threat to your skin’s pH and acid mantle. They’ll make your skin feel smooth at first, but it’ll be disturbed and rough in the long run.
That tight, squeaky-clean feeling you might experience after washing your face is the truest sign of cleansers with a high pH and damaged skin barrier. They, as well as other alkaline skin-care products, tend to strip away sebum and natural oils. As a result, undesirable effects such as redness, inflammation, scaling, and dryness can occur. Your skin might even break out, just because you cleansed with an alkaline face wash.
Low pH (1 to 6)
Because products with a low pH are at a level closer to skin’s natural pH, they will more effectively work with your skin and help cell turnover gently. They’re more likely to keep skin bright and smooth, instead of flaky and angry.
However, certain products can be too low of a pH for skin and irritate it. At-home peels and other acid-spiked products like to tend to have a lower pH level, making them great exfoliants but just as stripping as products with a high pH.
Cosrx, in particular, counteracts the stripping nature of acids with soothing ingredients that still maintain a low pH. As for its low pH cleanser, Cosrx’s lab researchers share that they use a milder form of surfactant derived from natural ingredients to cleanse thoroughly without irritating the skin.
What’s the ideal pH for skin-care products?
You obviously want to look for skin-care products with a pH of 5.5. If anything, they could be as low as 4.5 and as high as 7. The general rule is “slightly acidic is preferred for the best complexion”. If you are unsure of what exactly the pH of your favorite skin-care product is, you can check by literally pH-testing them with litmus paper.
You should try testing the pH level of your products before you use them, and its never too late to change your products to organic ones. Not only organic products will be healthy for your skin but it will also balance out the pH of your skin for a beautiful glow.