Why Your Skin pH Is So Important: A Dermatologist's POV

Your skin's pH level is of utmost importance and how you choose skin care products and carry out your daily skincare routine can either help or hurt this ideal, slightly acidic pH range.  Knowing why the pH of your skin matters and how to achieve the right balance of skin surface acidity can mean a more healthy and more beautiful you.  While you probably never thought about the concept of the pH of your own skin, take note of some simple practices to keep the skin's protective barrier at peak performance.

Your Skin's Security System, The Acid Mantle

This acid barrier which resides at your skin's top layer, keeps your skin's ph balance tightly regulated (until something disrupts it).

Your skin is naturally at its best when it can preserve a slightly acidic pH range. The outermost layer of the skin, known as the stratum corneum , has a "protective shield" of acidity which maintains your overall skin health.

But this pH balance can get thrown off and everyday actions and exposures can tip this acid set point and lead to skin conditions such as dryness, eczema, sensitive skin and even acne. While your outsides are acidic your insides not so much. Your skin ph levels are slightly acidic, however internally, your body thrives in a slightly alkaline pH range.

Your skin provides a barrier function that is maintained by what is known as the skin's acid mantle with a pH between 4.5- 5.5. The origin of the term acid mantle dates back to 1928. As a dermatologist, I am keenly aware of the importance of this acid barrier.  But few, if any, of my patients have ever heard the term. 

The first step in taking care of the skin's pH balance is knowing what it is and how to take the best care of your skin. Here is a primer on pH.

You may have learned about acids, bases and pH in middle school or high school science class. Did you ever do experiments in class using litmus paper to determine pH? Did you learn about acidity and alkalinity of the world around you? Well, even if it is not ringing a bell, here is a quick lesson. For a deeper dive into potential hydrogen or pH check out this online class.

Just as temperature is measured in celcius or farenheit with a wide range from freezing to boiling, different substances and living surfaces have what is known as a pH reading that shows a range from acid to neutral to alkaline.

The term pH stands for "potential of hydrogen" and has to do with how substances provide or take away hydrogen ions when interacting with other substances.  The pH of the skin is about 5.5 which places it at slightly acidic on this scale. Different body parts may vary narrowly,  but are between 5.6 on the upper arm and 6.22 around the inner thigh and groin, for example. Internally, things are different and the pH of the blood in your body is 7.4 which is just a bit alkaline.

Measuring pH, uses a scale from 0-14 where neutral pH is 7.0. 
Anything above 7 is an alkaline pH level
Anything below 7 is an acidic pH level

pH Levels of Common Substances You Encounter Every Day

  • Ammonia 11
  • Black Coffee  5
  • Bleach  13
  • Baking Soda  9
  • Lemon Juice  2
  • Most bar soaps  9-10
  • Shampoo 3.5-9
  • Pure water  7
  • Vinegar  2

You can test substances for their pH level but using ph strips that are available in drugstores or online.

Some skin care products may show pH values of their formula on their packaging.

What Does The Acidic Barrier, The Acid Mantle, Do For You?

The acid mantle keeps bad stuff out:

Thank your acid mantle for keeping out what should be out, like bacteria and fungi while it keeps in what should be in, like natural oils and moisture. It also has a key role in fighting free radicals, keeping things like pollution and sun damaging ultraviolet rays from causing skin harm. The acidic pH of your skin maintains skin health and bolsters its barrier function. I refer to the acid mantle as a "built in skin security system". The intruders that the acid mantle fends off also include allergens and chemical irritants by keeping them from penetrating the "force field" of acidity that the skin surface maintains. The acidity levels of your skin also play a key role in fighting off infection by allowing desired bacteria to flourish and reducing the growth of undesirable bacteria from gaining prominence on the skin surface.

The acid mantle helps nurture the skin microbiome this way:

Keeps out offending microbes like "harmful bacteria" (aka pathogenic bacteria), fungi/yeast

Keeps good microbes intact  "good bacteria" (aka commensal bacteria or symbionts)

And... the acid mantle keeps good stuff in:

The slightly acidic pH of the acid mantle maintains skin hydration and prevents water loss from the deep layers of the skin. It also repels skin dryness by regulating oil production allowing the skin cells to produce and hold on to ceramides and other lipids which are essential to skin integrity and proper function, not to mention softness and beauty. The skin acidity also helps to control cell turnover. Picture a conveyor belt carrying your Amazon packages at the distribution center. If it moves too fast, the packages will pile up and fall off, making a mess and ruining the boxes. If the conveyor belt moves too slowly the packages do not get to you on time and stack up waiting for transit. Now think of your skin in the same way. If the cell renewal is too fast it can lead to flaky that is shedding too much or if cell renewal is too slow you end up with dull thick skin.

What makes the skin pH unbalanced?

Household products like most laundry detergents, cleaning solutions are alkaline, With repeated exposure can tip the skin acidity off and allow the balance of the microbiome to favor bad bacteria which in turn can lead to skin issues like peeling, redness and other signs of irritability. Harsh chemicals like lye in drain cleaner and harsh cleansers have high pH levels and exposure to these caustic chemicals can be perilous to your skin with prolonged or repeated exposure.


External factors that can alter skin acidity
  • ​Allergens
  • Bar soaps with alkaline pH 
  • Long hot showers
  • Prolonged friction or rubbing of the skin
  • Pollution
  • Ultraviolet rays
  • Caustic chemical exposure

Internal factors that can alter skin acidity
  • Aging skin: the aging process sees the skin pH tends to increase
  • Skin type: some people produce more sebum oil in their skin and tend to maintain an acidic ph with ease
  • Diet: more studies are needed but diets high in processed foods may harm the microbiome

Some of the skin problems we find most bothersome, fine lines, dry skin, sensitive skin and acne can all be rooted in perturbation of the skin's barrier function and the best way to help this is seeking the proper pH level of your skin. A healthy skin pH is around 4.7-5.0. But many of our products both ones we apply directly to our skin surface and those we come into contact with external 


The great news: skin can bounce back. So even if you have been using products or doing harsh cleansing, when you switch up to good practices, the balance will most likely return to a acid ph


Follow These Dermatologist Recommended Tips for Keeping a Balanced Skin pH and Achieving Your Best Skin Yet

  1. Cleanse gently and not too often. While skin hygiene is important, there is such a s thing as too much cleansing. By using harsh soaps or cleansing too often, you can disrupt the skin barrier and raise skin pH
  2. When showering, use lukewarm water or tepid water, not extremely hot water. Also limit showers to less than 15 minutes. Hot water exposure for prolonged periods of time increases skin pH and strips skin of its natural oils.
  3. Check the pH of your skincare. In general cleansers that contain lactic acid, glycolic acid, citric acid and salicylic acid tend to be low pH products that can help maintain the skin's natural pH of around 5.
  4. Higher pH cleansers are typically bar soaps that contain sulfates and detergents (great for cutting dirt and grease from working hands, but harsh for the skin).
  5. Vitamin C serums have many benefits for skin health and beauty and can also help keep the slightly acidic skin pH that is desired.
  6. There is an important role in choosing and using the right products on your skin. By avoiding cosmetic products that are too alkaline and checking the pH of skincare products you select,  you can avoid disturbing the ideal pH level. Look for pH-balanced products.
  7. Avoid antibacterial soaps and sanitizers that contain triclosan.

    Is exfoliating a good thing for the skin?

    Gently exfoliating the skin is good and can aid the acid mantle... but only when done in moderation -1 or 2 times per week- and should be followed up by application of moisturizer.


    What is a harsh soap?

    So-called "harsh soap" will be a high pH cleanser, and contain high levels of surfactants like sodium lauryl sulfate, artificial fragrance or added perfume.

    Surface Deep Anti-Odorant is an aluminum- free deodorant brand based on the concept of maintaining the skin's acid mantle. When you take care of the surface pH and microbiome, the results are deep. I invented this anti-odorant formula that prevents odor all day and is a non- irritating and pH balancing method to keep skin clean and smelling fresh, naturally.