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How the skin barrier works

How the skin barrier works

The skin barrier sounds like a simple concept, but is actually quite complex when you get into the details. There are a lot of parts that go into making it function properly, and each of those parts works with the others to strengthen the skin. One such part is something called the "moisture barrier." But what exactly is that, and how does it relate to the larger skin barrier? This is where it takes a bit of nuance.

We refer to the skin barrier as brick and mortar. The bricks are dead skin cells, and the mortar is the fat. It's almost like a wrap around the body. But your barrier isn’t just a simple brick wall: It's a living, dynamic defence system and to understand the moisture barrier, you need to understand all that works with it and around it.

What is the moisture barrier?

The moisture barrier is an outer layer of skin that ensures your skin is hydrated by trapping and holding water. One of the ways your skin dries out is when water escapes your barrier and evaporates into the surrounding air, called trans epidermal water loss. So, keeping that moisture layer strong is essential to overall skin function.

What makes up this moisture barrier? A combination of proteins from dead skin cells and lipids. To go back to the brick-and-mortar analogy, if there was a part of the skin that resembled the brick wall, it'd be this. The proteins are things like collagen and keratin, and the lipids are your skin's natural oils and waxes (sometimes collectively called the lipid layer), such as squalene and ceramides.

How does it relate to the skin barrier?

The barrier isn't only this brick-and-mortar part. There are actually four main components to the skin barrier. It also contains components such as the skin microbiome, acid mantle, and the skin's own immune system.

The moisture barrier (or stratum corneum) is the outermost layer of the skin and is made up of lipids and proteins. This is the layer that keeps in hydration.

The skin microbiome is the trillions of microorganisms that reside on and in our skin. The skin microbiome is highly complex in itself, but greatly contributes to overall skin and body health.

The acid mantle is the thin, slightly acidic film that covers the skin. It is a mixture of your natural sebum (oil) and sweat. The pH range of the skin on your face and body fluctuates between 4.7 and 5.75.

The skin’s immune system (yes, the skin has its own immune system) incorporates elements from all of the above, as well as skin resident immune cells and free radical fighters (like antioxidants).

All these parts work together to fortify and support each other. For example, the skin microbiome is able to help produce by-products (called post biotics) such as lipids and peptides to feed back into the stratum corneum. On the flip side, when one is weak, it can hinder the rest. For example, if the acid mantle is disrupted, it can change the microflora of the biome or strip the moisture barrier of lipids.

And why is it so vital to tend to all these parts? Because a strong skin barrier literally means a better protected body. It protects us from mechanical injury, low humidity, cold, heat, sun, wind, chemical exposure, bacteria, viruses, fungi, and other pathogens.

A healthy barrier is critical to normal skin function.

As with most things in health: Knowing the full, robust structure of the barrier can help us better understand how to help and care for it.

How does it become damaged?

A lot can affect the moisture barrier, from things in your control to elements well beyond. You'll notice that your barrier has become compromised or weakened if it's easily irritated, inflamed, burns, or reacts to things that it used to tolerate. Here are the main components to be mindful of when tending to the moisture barrier.

  • Harsh soaps & hot water. Much of the damage to the moisture barrier happens in the shower or wash: Sulfates and strong soaps strip the skin of its oils and damage the proteins. Hot water can also dissolve the skin's protective oils.

  • Over exfoliation. Exfoliation is the act of removing dead skin cells from the stratum corneum. Doing this to a degree is a good thing, as it can make the skin appear vibrant and encourage cell turnover; but when you go overboard, you're removing those precious proteins and lipids that make up the outer layer of the skin.

  • Lifestyle habits. Not staying hydrated internally has been shown to affect the skin's dermal density. Additionally, things like consuming drying liquids (caffeine, alcohol) can contribute to internal dehydration. Finally, things like smoking can harm the barrier.

  • Sun exposure and pollution. Environmental stressors bombard the skin with free radicals and oxidative stress.

  • Skipping hydrating topical's. If you forget to apply face cream or body lotion post-shower or wash, that will do a number on the barrier and contributes to trans epidermal water loss.

How to care for your barrier?

The good news is that even though there are several things that can damage the barrier, it's a resilient system and can spring back to good health with some care and attention. And as we've noted, the skin barrier and moisture barrier are complex systems, so nurturing them will take a well-rounded approach. You'll notice your moisture barrier is healthy when it's bright, supple, feels hydrated, and is resilient to most changes. Here, some of the top ways to help your moisture barrier:

1. Hydrate with smart topicals

A well-formulated hydrator will do wonders for your skin and moisture barrier. Look for options with a robust assortment of moisturising botanicals and lipids to feed that lipid layer. There are many solid ingredients out there, so just look for those you like the texture and appeal of. A few to keep in mind: Aloe vera is a lightweight humectant, shea butter is a rich fatty-acid-filled butter, oat oils and extracts are ideal for sensitive skin, or squalane works well with your skin's natural oils.

Additionally, look for options that not only treat the moisture barrier but also tend to the other areas of the skin barrier. Biotic ingredients can feed and nurture your skin's microflora, helping support the balance, calming the skin, and improving the overall health of your skin. Antioxidants like vitamin C, E, coenzyme Q10, and fruit extracts can support your skin's immune system and neutralise free radicals. Finally, make sure you're using a formula that keeps your pH relatively stable, so as not to disrupt the acid mantle.

2. Adjust lifestyle habits if needed

We can't avoid all external stressors, and we'd never recommend you try. But you can make habit tweaks to ensure you're helping your skin deal with the onslaught of free radicals that come with these stressors. First up, stop smoking (full stop!). Also, do your best to drink your fill of water and balance dehydrating liquids. Be mindful of your sun exposure by wearing mineral sunscreen, avoid excessive sunbathing and exposure, and cover up with sunglasses, hats, and appropriate clothing if you're going to be in direct sunlight.

3. Support your skin's proteins and lipids internally

Given your moisture barrier is made up of proteins from skin cells and lipids, feeding your body a supporting supply of them can help your overall skin health. Look for collagen supporting foods, a wide variety of healthy fats, and of course skin supporting antioxidants. All of these can support your skin barrier from the inside out.

If you want extra help, collagen supplements contain amino acids (the building blocks of proteins) and can help the body produce its own collagen. Or you can look for skin supplements with lipids like phytoceramides or healthy fats like omega-3s.

The Vintage Avenue Team x

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