Skin barrier 101

In the past few years, the term “skin barrier” has been popping up everywhere and for good reason. A strong, supported skin barrier is integral to healthy skin, whether you’re treating acne, preventing wrinkles or just trying to achieve a radiant glow. But to truly understand what your skin barrier is and why it’s important, we need to bypass the barrier and look at what’s happening underneath the surface. Don’t let the science-y terms deter you!

The epidermis, keratinocytes and corneocytes

Your skin consists of three layers: the subcutaneous layer, the dermis and the epidermis. The epidermis is the outermost layer (remember the old school yard taunt “your epidermis is showing!”) and itself is composed of many, many layers of skin cells, known as keratinocytes. Your skin is constantly creating new keratinocytes at the bottom of the epidermis, which travel upwards, hardening and eventually being sloughed or exfoliated off. These hardened, dead skin cells are known as corneocytes. 

Before they are exfoliated off the surface, your corneocytes form the most outermost layer of your skin, called the stratum corneum, or horny layer (yes, that’s the scientific term). If you’ve ever heard the brick and mortar analogy, corneocytes are the bricks. The mortar, which holds the “bricks” together, is composed of lipids. 

Understanding lipids

Lipids are naturally occurring fats that are necessary for barrier strength and function. Though they are naturally occurring, lipid production slows down with age, so we use topical products to replenish their supply. There are three main lipids found in the stratum corneum (the brick and mortar outer, outermost layer):

  • Cholesterol: aids with recovery, healing and elasticity. This is different from, and will not impact, the cholesterol in your blood.
  • Ceramides: help retain moisture and increase hydration levels, soothing flakes and texture. Very common moisturizer ingredient. 
  • Fatty Acids: assist with maintaining overall lipid balance, supporting cellular functions and preventing water loss. 

Bringing it back to the skin barrier

Now that we understand the main components, we can talk about the skin barrier and more easily understand its importance. The skin barrier refers to the stratum corneum, or that outer, outermost layer of hardened skin cells (corneocytes) and lipids. 

The skin barrier, as you’ve heard many times before, is your body’s first line of defense against the outside world. It also impacts how your skin physically looks and feels.

When your skin barrier is working optimally, it prevents water from evaporating off the surface and keeps it in your skin (check out this article to learn more about dehydrated skin). It keeps out environmental stressors, such as pollution, allergens, bacteria and lessens the power of UV exposure (you still need sunscreen!) Lipids also provide antibacterial and antimicrobial support. 

A healthy, happy skin barrier literally translates to happier, healthier looking skin. Lipids keep your skin smooth, supple and elastic. Increased water retention plumps the skin, making it fuller. 

Ultimately, all of these benefits together reduce the risk of acne and increase your body’s ability to prevent and respond to it, allowing lesions to heal faster (to learn more about your skin barrier and acne, read this).

When your skin barrier is damaged, your skin is vulnerable to infection, inflammation, irritation, dryness, tightness, increased signs of aging…basically everything you don’t want. 

How to damage your skin barrier

Your skin barrier can be damaged in any number of ways: over exfoliating, stripping cleansers, sun exposure, hot water, pollution, humidity and temperature changes, stress, lack of sleep and genetics. So, yes, basically anything. But remember, your skin barrier is explicitly designed to withstand all of these things, which is why we need to take care of it in the first place. It’s only when we are not being mindful of supporting our skin barrier that these internal and external factors can wreak true havoc. 

Another good thing about our skin barrier is that it’s right where we can see it and feel it, making it easier to identify when something is out of balance. Signs of a damaged skin barrier include dryness, itching, redness, peeling, increased breakouts, stinging and burning. 

How to repair your skin barrier

If you experience any of the symptoms above, feel like you can’t get breakouts under control or feel stinging when applying even the most basic moisturizer, it’s time to take a step back and repair your barrier. 

Since your skin barrier wants to do its job as a protective barrier, it’s naturally going to work towards achieving this goal. In response to damage, it will try to up the production of lipids and activate your skin’s wound healing response. But those processes can only be as effective as you let them, so you need to give your skin time to repair and help it along with certain topical products. 

Discontinue the use of anything exfoliating, drying or stripping. Use a gentle cleanser, moisturizer and never, ever forget sunscreen. Your skin can’t do anything if it’s trying to fight off the sun! Replenish your skin’s lipids with moisturizers that contain ceramides, cholesterol and fatty acids and restore hydration with hydrating serums with ingredients like hyaluronic acid, glycerin and panthenol. You can find a number of barrier-repair products with soothing ingredients like colloidal oats, green tea and allantoin.

Be patient with your skin as it repairs itself. Once your skin shows signs of restoration, take it slowly or risk undoing your progress! Introduce active products slowly, one at a time, and continue to support your skin with barrier repair products. 

Of course, the best way to avoid a damaged barrier is to nurture it in the first place! This is especially important as you age and your skin slows down lipid production and retention. A healthy barrier makes all of your products work better and to their full potential. Couple your active products with nourishing, moisturizing ones and keep barrier-supporting products in regular rotation.