Skin Barrier 101

In recent years, the spotlight has really hit skin barrier replenishing products, which we're honestly so happy about. But what exactly IS the skin barrier?

What we typically refer to as the skin barrier (AKA the lipid barrier) is really a trio of epidermal lipids that essentially occupy the space between skin cells of the topmost layer of skin only, the Stratum Corneum, to maintain structure, suppleness, and overall strength. These three lipids are: ceramides, cholesterols, and fatty acids that are all produced by keratinocytes (keratin-producing cells). Their main functions include preventing water, mineral, and electrolyte loss and defense against microorganism invaders. These epidermal lipids are not to be confused with sebaceous lipids, which come from sebum and have very different functions in maintaining surface hydration, etc.

Your lipid barrier can become weakened due to various reasons. Essentially, over-washing, over-exfoliating (chemically or physically), over-applying actives, allergic and adverse reactions, sun damage, etc. Harsh, stripping ingredients that can damage lipids will also compromise the barrier, including high-concentration detergents, pollutants, allergens, but even more pertinently, all of our favorites: AHAs/BHAs and retinoids.

How do you know if your skin barrier is compromised? You can tell that your barrier is damaged if your skin constantly feels or looks tight, dry (but may still overproduce SEBUM—or oil), itchy, red, blotchy, or dehydrated and—this is the important part—nothing seems to be working.

Okay, now how do I fix my skin barrier? Enter: barrier repairers. They work to retain moisture, rebuild the barrier, and reinforce it to prevent further damage. They will also help your other treatments do their jobs more effectively without causing secondary damage!

Ingredients to look for that all either directly or indirectly replenish the lipid barrier:

-Ceramides

-Cholesterol

-Fatty Acids: this includes fatty-acid rich oils and fatty-acid derivatives such as linoleic, oleic, linolenic acids

-Lipids (similar to fatty acids): phytosphingosine, sphingolipids, phospholipids, glycolipids, etc.

-NMFs (Natural Moisturizing Factors)

-GAGs (Glycosaminolglycans): hyaluronic acid, collagen, and elastin

-Amino Acids: GHK-Copper peptide, any of the 20 natural amino acids, other peptide families