The barrier layer of the skin (also known as the stratum corneum) is our body's natural protection against environmental stressors such as bacteria, viruses, UV light, pollution, and more. It also regulates moisture levels, helping our skin feel balanced, nourished, and healthy. Most of the time we leave it up to nature herself to perform all these tasks, and most of the time the skin carries out these duties with quiet efficiency.
However, in our work with clients we are seeing more and more instances of skin disorders that can be traced back to a breakdown of barrier function. Simultaneously, we’re seeing a lot of marketing claims from skincare brands that say their products support barrier function without demonstrating an actual understanding of what this entails (or whether their products even deliver on that promise).
So we wanted to take this opportunity to clarify what “barrier function” actually means, how it works, and what you can do to not only support it, but actually improve it. Because here’s the thing – if you don’t have healthy barrier function, you don’t have healthy skin. Period. It won’t function well, and it certainly won’t look good.
Understanding barrier function starts with having a look at the components of the barrier layer. The “barrier layer” of the skin protects us from trans-epidermal water loss (TEWL), balances the moisture levels of the skin, creates an ecosystem for bacterial harmony, minimizes inflammation, and normalizes immune function. There are many things that can contribute to barrier dysfunction (including exfoliation, which we will get to later), but at the top of the list is failure to supply the nutrients necessary to support proper functioning.
The two main components that must be plentiful for the barrier to function properly are barrier lipids, which include ceramides, fatty acids, and cholesterol; and natural moisturizing factor (NMF), which includes amino acids, urea, lactic acid, and other water-soluble compounds. (You can think of it this way: moisture + hydration + pH balance.) When we are healthy our bodies produce these substances naturally, so it makes sense to equate insufficient supplies of necessary ingredients with barrier function breakdown.
The signs of barrier dysfunction can include dry skin, dermatitis, and rosacea, and the common denominator underlying all of these conditions is inflammation.
Barrier dysfunction can pave the way for pathogenic imbalances in the microbiome, and allow easy access for viruses entering through the mouth, nose, and eyes. These mucous membranes, abundant in blood vessels, mucinous glands, and serous glands, are a humid environment that is just right for viral and/or bacterial colonization. To add to that, the new normal of wearing masks creates yet another dark, warm, humid, and virus/bacteria-rich environment around the mouth. The oral microbiome is loaded with potential pathogens, and trapped exhalations of air from the mouth create an environment well suited for pathogenic growth, so it's no wonder we're hearing about the rising incidence of maskne.
It’s interesting that after decades of dermatological research we’ve only very recently started to pay attention to the stratum corneum, the very top layer of the skin. When we look at skin we are very literally looking at the barrier layer, but ironically it has received little attention. Apparently we were all so busy deep dermal mining – examining fibroblast behavior, extracellular matrix structure, and sebaceous gland activity among other things – that we overlooked what was right in front of us the whole time.
We took the stratum corneum for granted, or even worse, we mistreated it without considering the possible consequences. We scraped away at the skin’s surface with aggressive scrubs and chemical exfoliants at home and went to spas for microdermabrasion treatments because we were told doing so would increase cell turnover rate, decrease acne breakouts, improve dermatitis issues, and make dull skin brighter. If the treatments didn’t seem to be “working” the answer was that we needed to do more of it, more often. All of which has turned out to be utterly wrong.
If we had our way we would consign the “exfoliation/deep cleansing improves your skin” advice to the scrap heap of derisory myths that have been fully debunked, right up there with “the earth is flat” and “whacking off makes you blind.” Really, it’s past time we did away with the practice of exfoliation. The only reason exfoliation as a skin care method has lasted this long is because skin care companies need something to sell. However, at this stage in scientific research, exfoliation has as much credibility as the radium cure, which made the rounds in the early 20th century and actually killed people.
You’ll be happy to know that shrugging off exfoliation doesn’t leave you bereft of helpful skin care choices. However, the path is littered by obstacles set up by marketing eager beavers. If you have dry skin, acneic skin, some kind of dermatitis issue, including maskne, or are past the age of thirty, improving barrier function should be a real goal. Just be careful what you shop for. And please don’t conflate products claiming to support the barrier with products that actually improve barrier health. The first set are born of marketing spin, while the latter are born of and borne out by research. The upshot is that not all products are created equal – but how do you tell the difference?
Products claiming to support the barrier can include ingredients that act as occlusives, like petroleum jelly or shea butter, that prevent moisture from evaporating. They can also include moisturizers that are high in humectants, like glycerin and hyaluronic acid. If the moisturizers contain fatty acids like safflower or sunflower oil, even better – that means you are getting some barrier support, as some of these ingredients form part of the barrier layer. (Side note: Marie Veronique does not use petroleum jelly or any other mineral oil-based ingredients in its products due to concerns regarding carcinogenicity.)
However, products that support barrier function are not the same as products that are specifically designed to improve barrier function. Products aimed at barrier repair contain ingredients that are already the constituents of the stratum corneum, which consists of barrier lipids and cellular walls. You can think of the stratum corneum as like a brick wall made up of corneocytes (skin cells) that are held together by grout (lipids). To keep this wall in good condition you need ingredients like ceramides, cholesterol, and free fatty acids to replace lipids in the lipid barrier. You also need ingredients that replace natural moisturizing factor (NMF) in the corneocytes that make up the cellular walls of the top layers of skin. These ingredients are amino acids, lactate, urea, and various minerals.
The difference between barrier support and barrier repair is the difference between throwing concrete at a crumbling wall in the hope something sticks to repairing the wall using the right building materials. Quite a distinction!
Our company is much more interested in doing actual repair work than in papering over cracks. Why? Because we know it can be done. And how do we know this? Because we are conversant with the science that is showing us the way. Being at the forefront of applying research and the biomimetic approach to real life products is very exciting for us. It also happens to be the future of skincare.
We created our Barrier Restore Serum because, even amidst an ocean of existing skin care products, it was something the world was sorely lacking.
This product was formulated to restore natural moisture regulating function, aka barrier function, to the skin. Hydrating from the outside with water-based sprays doesn’t do it, nor does applying occlusive creams that trap moisture below the surface – in fact, these methods can make dehydration worse over the long run. You may have noticed that applying creams can make your skin feel drier, causing you to keep applying even more without ever seeing improvement, until it becomes a vicious cycle. This is because you are just trapping water without actually improving barrier function.
Barrier Restore Serum improves barrier function in two ways: first, it replaces NMF, that collection of water-soluble compounds that keeps skin cells hydrated. Secondly, it prevents loss of NMF via a liposomal sealing system that traps water molecules instead of letting them absorb into the lower layers of the epidermis.
By applying this serum morning and night you are not only providing essential nutrients for healthy skin, you are also reducing the risk of unwanted symptoms that arise from barrier dysfunction, such as dry skin, dermatitis, acne, rosacea. You are bolstering your body's innate defense system, which prevents infection from external pathogens. We recommend applying Barrier Restore Serum as the last of your serums (or after cleansing/misting if using alone) and just before applying one of our oils. If oils aren't your preferred method of moisturizing, this serum can be used as the final step of your regimen (perfect for hot, humid summer days), making it an extremely versatile product, appropriate for all people, of all skin types.
The results of using Barrier Restore Serum are based on achieving long term skin health. Though the skin is nourished instantly, resulting in a radiant glow, the list of benefits it offers are well worth the wait of prolonged usage. In our practice we find that most people have inadequate barrier function, often accompanied by dermatitis issues. This can be classified as unhealthy skin. As we age, barrier function declines, so it’s also quite possible to have healthy skin that exhibits normal signs of aging like increased dryness and wrinkles. Thus it falls to almost every skin that using Barrier Restore Serum will improve its health and appearance. This is of course in addition to using topical retinol and Vitamin C. An ideal topical regimen would include these three products – you can call them the (Kristina) Holey Trinity. Haha.
When you’ve achieved a healthy barrier layer function you witness a whole host of benefits: an increased rate of healing, even texture across the face, an absence of dry patches, and fewer fluctuations in skin comfort when moving between different climates, extreme temperatures, or elevations (or even long haul flights). And that’s just on the surface.