Irritated skin
Meet the acid mantle

Skincare 101: What Is The Skin Barrier?

You’ve likely heard the term “skin barrier” buzzing around the skincare industry by now, but what exactly is it? Why is it important? And what happens when it becomes damaged?

We’ll tell you what the skin barrier is, what it does, and what happens when it becomes damaged. We’ll also give you tips for preventing a damaged skin barrier.  

What Is Your Skin Barrier?​

The skin barrier is the outermost layer of your skin.

Our skin is composed of three layers:

  • The epidermal barrier (outer layer)
  • The dermal layer (middle layer)
  • The subcutaneous fatty layer (deep layer)

For skincare, let’s focus on the epidermal layer. 

The epidermal barrier consists of five smaller layers called the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. The stratum corneum is the outermost layer of the epidermal barrier, comprising 20-30 layers of dead cells and keratin. 


The stratum corneum is the layer of your skin that you apply skincare products to.

Functional skin barrier with proper hydration levels easily repelling toxins and bacteria from entering the epidermal layer.

What Is The Skin Barrier’s Function?

Your skin barrier is a protective layer of skin that acts as the first defense for your body. The two main ways your skin barrier defends you are its keratin wall and the acid mantle.


The skin barrier is made of a tough protein called keratin that acts as a strong wall on your skin and doesn’t allow harmful toxins to pass through. The skin barrier also has a film over it that has a slightly acidic pH, referred to as the acid mantle, which helps kill harmful microbes. In other words, the acid mantle is a thin film on the skin’s surface composed of amino acids from your sweat mixed with lipids from your oil glands. Along with the microbiome, it’s part of the delicate system that creates a healthy skin barrier. The skin barrier protects you from:

  • Harmful toxins – The acid mantle helps kill harmful bacteria that contact your skin.
  • Excessive transepidermal water loss (TEWL) – TEWL is the amount of water that evaporates through your epidermal barrier and a healthy skin barrier protects you from excessive loss.
  • Effects of UV light damage – UV light damage can cause sunburns, lesions, and skin cancer, and your skin barrier functions as a shield from these harmful rays.
A broken skin barrier with high transepidermal water loss. Water evaporates through the epidermal layer and allows toxins in.

What Causes A Broken Skin Barrier?

Several factors can cause a broken skin barrier and here are a few:


  • Harsh Soaps – Using detergent soaps and aggressively scrubbing your face can damage your skin barrier.
  • Environment Aggressors – Too dry or too humid weather, over-exposure to UV rays, or extremely windy conditions can disrupt the skin barrier.
  • Body Stress – A lack of sleep, a stressful environment, and a poor diet can impact the skin barrier.
  • Genetics – Our skin health is largely determined by variables outside our control, like genetics or aging. These factors can potentially cause a broken skin barrier.  

Damaged Barrier Signs:

Here are a few signs that you may have a broken skin barrier:

How To Prevent a Broken Skin Barrier

Step 1: Evaluate your Skincare Routine by avoiding overly harsh detergent soaps, be careful about how often you exfoliate, and assess how many active ingredients you are using at once. While exfoliating and using active ingredients aren’t harsh on their own, you want to always be gentle with your skin and not overdo it. Choose ingredients such as squalane, niacinamide, hyaluronic acid, colloidal oat meal and ceramides.

When using active ingredients, make sure they are safe, of high quality and contribute to a healthy skin barrier like our Hi-Function Foundation and Oil-Balance Booster.


Step 2: Do your best to give your skin a break from harsh environments. If you can’t avoid a too hot or too humid environment, then properly prepare your skin. Always use SPF, use hydrating serums to preserve your skin’s water levels, and wear protective clothing.