Moisture Barrier In The Skin: What It Does & How To Help Care For It

"We were taught initially that the skin barrier is this brick and mortar. The bricks are dead skin cells, and the mortar is the fat. It's almost like a wrap around the body. And just in the last couple of years, we know that it's so much more dynamic than that," says board-certified dermatologist and mbg Collective member Whitney Bowe, M.D. Your barrier is not just a simple brick wall: It's a living, dynamic defense system with several commingling teams and players. And to understand the moisture barrier, you need to understand all that works with it and around it. 

So 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 I alluded to in the introduction, if there was a part of the skin that resembled the brick wall, it'd be this. (I told you it wasn't an entirely inaccurate visual!) 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. To get technical, this moisture barrier is called the stratum corneum—and when you look at renderings of the skin, you'll see it's the outermost layer of the epidermis.

Let's break it down:

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. 

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. 

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: 

Additionally, we recommend looking 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 neutralize free radicals. Finally, make sure you're using a formula that keeps your pH relatively stable, so as not to disrupt the acid mantle. 

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.    

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.

Your moisture barrier is a critical part of the overall skin barrier function, and to care for one part means to care for all. The moisture barrier itself (also called the stratum corneum) is the layer made up of proteins and lipids that traps in water and keeps all below it protected. While it can become damaged by harsh topicals and outside stressors, you can care for it with smart topicals and lifestyle habits. If you want to learn more about how to care for your skin barrier function overall, check out our guide.