We asked experts about the importance of pH in skin care, and proceeded to test all of our products

After high school science class, I wasn’t planning on caring about the pH of anything ever again. A fascination with those rainbow-colored test strips notwithstanding, it just never seemed like something that would come up. But here I am with the aforementioned test strips and a very novice science lab set up before me—all in the name of skin care. It turns out that when it comes to skin care, pH matters. As someone who has to work hard to keep my skin clear, I wondered if balancing my skin’s pH was the missing key to perfect skin. 

But before we dive into that, here’s a mini refresher. Without getting lost in the minutiae of it all, pH is a scale that measures the acid-alkaline ratio of a substance from one (most acidic) to 14 (most alkaline). A pH of seven is neutral, so anything lower is acidic, and anything higher is alkaline. For scale, lemon juice lands at a two and ammonia is about an 11.5. The scale is logarithmic, which means that counting down below seven (neutral pH), each number is 10 times more acidic than the preceding number. The same is true above seven—counting up, each number is 10 times more alkaline.

So, how does pH apply to your skin?

Healthy skin has a pH of around 5.5, which is just slightly acidic. When skin is within the appropriate range, it’s at its most healthy. This is because the acid mantle, a mixture of sebum, sweat, and dead skin cells, covers your skin with a barrier that protects your skin from pollutants and keeps bacteria from producing. It’s important to keep this barrier intact—by keeping your pH balanced—because when your skin’s acid mantle is disturbed, it creates a suitable environment for dermatitis, acne, and candida infections.

My first clue that pH was important came when I saw it mentioned in the product descriptions on SokoGlam, a Korean beauty site. K-beauty emphasizes great skin and intensive routines, and if pH is a focus when creating those products, then pH matters.

To start off, I went right to the source of my inspiration—the co-founder and chief curator of Soko Glam, Charlotte Cho. First I was curious: what is it about pH levels that is so important in the formulation of Korean beauty products? In this case, it’s due to demand. “Korean consumers are very aware of their skin’s pH and that is why a lot of products have their pH level marked on the label,” shared Cho. She noted that it is important to them to balance the skin’s pH in order to reduce irritation and not strip the skin of its natural oils.

Explains Cho:

Even water can raise your skin’s pH, she says—and with so many factors in what can affect your skin, it’s important to pay attention to what you can control. “The longer your skin’s pH is left affected, the longer your skin is prone to exposure to environmental stressors and the growth of bad bacteria,” she adds.

When you have Charlotte Cho on the line, you ask about products. When dealing with an unbalanced pH, she recommends toners. If you’re going for a hydrated, dewy look, she recommends the Mamonde Hydrating Beauty Water. “It’s formulated with extracts from 100% organic Damask rose, the multi-tasking liquid calms and moisturizes as it tones (with a pH around 5.5) and preps the skin for the rest of your routine,” she says.

If you have oily, dull, or uneven skin, try d’Alba piedmont Peptide No-Sebum Balancing Toner. “The first listed ingredient is pearl extract, which brings radiance back to the skin while evening skin tone. It also hydrates and transforms oily and combination skin to a balanced, happy state with a pH level of 5.6,” Cho explains.

And no matter who you are, the Klairs Supple Preparation Unscented Toner is great for all skin types. It has a pH of 5 and will help prep the skin to better absorb serums because it clears excess dirt and sebum. If you’ve tried it in the past with poor results, try it again. “The formula has been improved to absorb faster, have a lighter texture, and have absolutely no fragrance, thanks to the removal of essential oils,” says Cho.

Is pH the secret to perfect skin?

But I was still wondering (Carrie Bradshaw voice), is proper pH the secret to perfect skin? To find out, HelloGiggles spoke with Dr. Bobby Buka, a leading dermatologist in New York City, and someone with a lengthy bio: he’s the founder of Bobby Buka MD Dermatology, contributing Founder & Chief Science Officer of the First Aid Beauty skin care line, author of Buka’s Emergencies in Dermatology, and the newly launched Top 50 Dermatology Case Studies for Primary Care.

First, the hard truth. Balancing the pH of your skin is important, but it’s not to the path to perfect skin. Instead, think of it as a good place to start. And it all comes back to that acid mantle we talked about earlier. “Our skin machine is humming, and when we keep the acid mantle intact, it means all systems are working optimally with the immune system at peak performance,” says Dr. Buka.

And there’s something else important to know, too. “Your skin’s pH doesn’t have to be corrected; it corrects itself,” says Dr. Buka. “All we can do is mess up the pH by applying products that are one extreme or the other.” Noted.

So while you can’t “fix” your skin’s pH with products, you can ruin it with too-harsh products at either end of the scale. Dr. Buka agrees that the pH of skin care products matters. “On the skin’s surface is a fine film called the acid mantle with an average pH of 4.5 to 6.7, slightly acidic. Skin care products should either match this or be pH-neutral (7) so as not to disrupt your skin’s natural protection from infectious pathogens.”

Now you’re probably wonder if your skin is pH-balanced.

The best way to know where your skin is balanced is by how it feels. “There are only so many ways your skin will show you it’s upset, so whether your skin’s pH is too low or too high, the results will be identical. First it will get red, then scaly, then blistery at worst,” says Dr. Buka.

And just because your skin is a little oily or dry, it doesn’t mean your pH is unbalanced. “Oil production is typically is a different discussion than that of pH,” says Dr. Buka. “If your skin is oily, a product that balances your pH may dry out your skin, but that’s not the best way to manage it.” In other words, attempting to “balance” your skin’s pH isn’t always the solution. “If your skin is oily, your glands are simply doing their job to protect you. Since upsetting this function will make your skin vulnerable, it’s not the most natural treatment,” he shares.

To recap, yes your skin’s pH is important. And yes, the pH of your skin care products is important. But while you can’t magically “fix” your skin’s pH level—it does that by itself—you can mess it up if you use products that are too far outside your skin’s natural pH.

This is where I tested the pH of all my skin care products.

From speaking with Cho and Dr. Buka, I learned that my skin, which is generally healthy outside occasional blemishes, was probably pH balanced. But still I wondered: was the pH levels of my skin care products optimal? So here I am, back in front of my makeshift science experiment, testing my products to find out if they are doing more harm than good.

The cleansers

I use Banila Co. Clean it Zero every day, and occasionally Vanicream Gentle Facial Cleanser when I need something stronger. These clock in at pH levels of 5.25 and 5.5 respectively. Fortunately, these get the all clear for my skin type—slightly acidic cleaners are recommended for those with acne prone skin.

Many cleansers can be too alkaline for skin, which is why you might feel “squeaky clean” after washing your face. If this is the case, ditch your current cleanser for one that falls somewhere around 5.5.

(Note: The Banila Co. formulation has since been updated. It’s now listed as a pH of 6.2, which still falls within an acceptable range for most skin types.)

The exfoliants and toners

While many of my everyday products are pH balanced, my beloved Biologique Recherche P50 is not—it has a pH of 3. One of P50’s claims is balancing the pH, so I took a closer look at how this works.

Some ingredients are pH-dependent, which means they can’t work to their full ability when they are formulated into a product outside of that pH. P50 is made up of various AHAs, whose potency increases when used at a more acidic scale. There’s also such a thing as AHAs being too potent, which we’ll get into more detail about when I talk chemical peels.

I tested and retested my bottle of Paula’s Choice 2% BHA liquid. The strip read a solid 4 to 4.5 every time, but the Paula’s Choice website says it actually ranges from a pH of 3.2 to 3.8. While my results aren’t far off, I wondered what why it tested differently. I learned that the pH of liquid can be affected by exposure to air, changes in temperature, or leaching of chemicals (like from the container it’s in). I’ve had this Paula’s Choice bottle for longer than I can remember, so it’s no surprise that the pH might have changed slightly.

The vitamin C

My beloved COSRX Triple C Lightning Liquid tested in at a solid 3, the same pH listed on SokoGlam. In this case, the low pH is a good thing. Vitamin C (ascorbic acid, in the case of this product) is more stable and has higher skin permeability at pH levels below 3.5. Like the increased potency of AHAs I mentioned previously, this is another reason why the pH of your skin care products is so important. If you are relying on a vitamin C product to brighten your skin or clear discoloration, you might be wasting your time and money if the product wasn’t developed with pH in mind.

The retinol prescription

While Curology doesn’t list the exact pH levels of their products, they estimate that any given mix will have a pH of 4-5. My Curology prescription, a mixture of .018% tretinoin, 1% clindamycin, and 8% azelaic acid, tested at a 6. This one gets the all-clear.

The oils and moisturizers

My morning moisturizer and SPF combo, the Murad Anti-Aging Moisturizer for Blemish-Prone Skin, comes in at a 6. This falls right in line with what it should be. This product uses a chemical sunscreen, but if you are using an SPF that uses a physical blocker, like zinc oxide, it needs to have a higher pH to be effective since zinc oxide degrades at lower pH.

While measuring the pH of my nightly facial oil, Herbivore Lapis, I learned something. Measuring pH for oils isn’t the same as measuring it for other liquids. This has to do with their non-aqueous nature, which goes far beyond the subject of this piece, and even further from what’s important to skin care. (But, if you’re curious, I first “measured” the oil at a 5.)

The chemical peel

My at-home chemical peel clocked in at the lowest pH, which is no surprise. The Make Up Artists Choice Mandelic/Salicylic Acid peel measured a 2.5 pH, which is about the same as lemon juice. Like I mentioned which discussing my exfoliants, the lower the pH, the stronger the acid, and the better it can do its job. Because this product has a higher acid percentage than daily-use exfoliants, you should only use it, at maximum, once a week (but I wait more like two weeks).

With my experiment now over, I’m happy to share I don’t need to get rid of any of my favorite products. If I’ve learned one thing, though, it’s that your skin is really good at taking care of itself. Though I might be angry at it when it acts up on me, sometimes being gentle is the best medicine.