beauty · skincare

Skincare Basics: The Acid Mantle

I’m getting the sense that you guys like reading about skincare. That works just great for me, because I love talking about it!

We’re going to level-up from talking about oil cleansing and talk about your skin’s acid mantle, how to protect or repair it, and how to incorporate acids into your skincare routine. If you’re experiencing adult acne, relentlessly dry skin, or sensitivity, it may be because you have a compromised acid mantle. The frustrating part is, the science and research is there about pH in skincare, but North American skincare companies don’t really reflect this research, so it’s up to us as consumers to educate ourselves and purchase based on science!


What’s an acid mantle?

The acid mantle, also called the moisture barrier, is the outer layer of your skin, the stratum corneum, which happens to be slightly acidic. It’s comprised of lactic acid, other amino acids, fatty acids, water, and other components. Most (healthy) skin is between pH 4.0 and 6.5. Water, which is neutral, is 7.0. The acidic outer layer of our skin protects our skin from the growth of acne-causing fungi and bacteria, which thrives in alkaline environments (pH above 7). Good bacteria, that keeps our skin healthy, thrives in an acidic environment. From all this information, you can see that it’s in your best interest to keep your skin slightly acidic.

Most healthy skin is between pH 4.0 and 6.5, where water, which is neutral, has a pH of 7.0. This acidic outer layer of our skin protects our skin from the growth of fungi and acne-causing bacteria, which thrive in alkaline environments (pH above 7).



What leads to a compromised acid mantle?

A healthy acid mantle means the pH of your skin is within the range of 4.0 to 6.5. A compromised acid mantle means the pH of your skin is outside this range – above 6.5. Using any cleansers, lotions, or creams with a high pH may compromise your acid mantle. You know all those posts telling you to put baking soda on your zit to dry it out? Baking soda has a pH of 9.0. Putting something with a pH that high will allow alkaline-loving bacteria to grow and make your skin worse. 


How do I know if I have a compromised acid mantle?

Some indicators that you have a compromised acid mantle:

  • Dry, flaking skin
  • Adult acne (despite general good health, diet, and exercise)
  • Redness and irritation
  • Generally sensitive and ‘tight’ feeling skin

These symptoms may point to a compromised acid mantle. Your skin is angry and trying to restore itself to a normal pH, but some of the products you’re using may counteract this.


How can I repair my acid mantle?

You can repair your acid mantle by carefully considering the products you’re using on your face. The number one thing I would recommend is incorporating an acid into your routine. Acids are primarily used as chemical exfoliants, but they have tons of benefits. When I mention using acid on my skin, people always recoil in horror, as if I were pouring something from a high school chem lab on myself and sizzling my skin off. No way! Skincare acids are painless and make your skin look glowy and awesome.

There are two types of acids: beta-hydroxy acids (BHA) and alpha-hydroxy acids (AHA).

Some features of BHAs:

  • Also called salicylic acid
  • Oil-soluble so great for oily skin
  • Reduces blackheads and pore size
  • Doesn’t increase photosensitivity (unlike AHA)

My favourite BHA is Paula’s Choice Skin Perfecting 2% BHA Lotion. Stridex also sells pads soaked in salicylic acid which are popular, although I have not personally tried these.

Some features of AHAs:

  • Includes lactic acid, glycolic acid, and mandelic acid
  • Water-soluble
  • Shown to increase cell turnover and collagen
  • Inhibits excess melanin (PIH leftover from acne)
  • Increase hyaluronic acid content in skin
  • Increases photo-sensitivity (downside)

AHAs are multi-tasking badasses. They’re great for anti-aging because they increase cell turnover and increase collagen (the loss of collagen is linked to wrinkles). AHAs also fade discoloration from acne marks (post-inflammatory hyperpigmentation or PIH). Also, AHAs can increase hyaluronic acid content in the skin. Hyaluronic acid holds water and makes your skin look glowy and happy. All these features, on top of keeping your acid mantle happy! AHAs are frickin’ incredible, guys.

It’s important to note that AHAs will make your skin more photosensitive (receptive to sun damage), so if you’re using AHAs, you need to wear sunscreen. No ‘scuses.

Here’s a more detailed thread on Reddit if you want to learn more about acids: 

If acids aren’t your thing, you can also cut out high-pH (alkaline) products from your skincare routine. In this blog postKerry from Skin and Tonics discusses only using cleansers with a pH below 5.5. Here’s a great list of popular cleansers and their pH, and here is a list of recommended low pH cleansers. The most popular one I always see on Reddit is the Cosrx Good Morning Low pH Cleanser. I don’t personally use a cleanser (oil cleanse only), but many people use a cleanser like this instead of the second oil cleanse.

Image result for cosrx good morning cleanser

What acid do you personally recommend?

My desert-island skincare product is Biologique Recherche P50 chemical exfoliant. It’s actually a mixture of AHAs and BHA – which confuses me, because they work optimally at different pHs, but after seeing the results, I don’t question it. This product keeps my skin acne-free and glowing. Yep, it’s expensive, but I don’t care. It’s worth it.

Image result for biologique recherche p50

You can read more reviews on P50 here  and here.

Paula’s Choice 2% BHA was my starter acid. Full disclosure, I had a lot of closed comedones when I started using a BHA. Closed comedones are the little blocked pores that form into small white bumps under your skin. Sometimes they get angry and surface as pimples. When I started using a BHA, these little white bumps surfaced one after another for about a month. This is referred to as purging, and while it totally sucked, after a month, my skin was clear and incredible. I don’t have any more closed comedones because of the acids. No regrets.

After using a BHA for a couple months, I incorporated the Biologique Recherche P50. I started every other night, and eventually worked up to every night.

One thing to note is that it’s hard to find Biologique Recherche online. It’s normally sold in spas. However, you can find it in Canada at La Chambre des Dames or at Rescue Spa for the States. The sites will make you log in to see the prices.  


How do I incorporate acids into my routine?

When applying an acid, it’s important to remember that acids work best at the low pH that they’re applied at. This means, adding another product directly overtop of the acid immediately will reduce it’s effectiveness. After applying an acid, always wait about 20 minutes before applying more products. The Acid Queen thinks that the wait time is unecessary but I’m going to continue with this method until I can gather more information. 

Here’s how you would incorporate an acid into your routine:

  1. Cleanser
  2. BHA or AHA acid (wait 20 minutes after applying)
  3. Serum
  4. Moisturizer / Oil
  5. Sunscreen (morning)

Note that a Vitamin C serum is considered an acid, and would be incorporated as #2, with a 20 minute wait time afterwards.

If you’re interested in incorporating both AHAs and BHAs, I would recommend alternating nights (BHA one night, AHA the next).


Phew, that was a long one! What are your favourite brands of acids? Leave me a comment or question below!



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