Lab Notes - The Regimen Lab Skincare Blog ?

Skin Barrier Repair - An Introduction

“Barrier Repair” has made its way into the mainstream of skincare, but is still pretty misunderstood and (as you’ll learn is a recurring theme with us) has not been well served by brands trying to market products. So let’s start with some definitions and a little philosophy.

“Barrier Repair” typically refers to the skin barrier, a term used to describe the various ways skin protects the body from the outside world (you should read our post about it if you haven’t already). There are numerous ways the skin barrier can be damaged - from UV and environmental damage, to overwashing - and barrier health is an important contributor to overall skin health.

The tricky thing is, once barrier damage starts, it’s hard to make it stop, because it works as a continuous cycle. It’s kind of like seeing what causes damage to your skin, stressing about it, and then realizing that your stress is causing the damage.

Step One: Prevent the damage in the first place

First thing’s first, start by removing or preventing the cause of barrier damage. Prevention is always easier than treatment.

Some of the top causes of barrier damage include:

  • UV Exposure
  • Picking / Scratching
  • Irritant Exposure
  • Harsh Environments
  • Pollution
  • (Poor) Skincare! (Overwashing, over exfoliation, Occlusion, Alkaline pH)
  • Stress

UV Exposure

We’re not the first to tell you that UV wreaks havoc on skin. Sunburn can completely disrupt the skin barrier, but even when using sunscreen properly, UV exposure can cause damage. We now know that Melanin has a protective role in UV exposure. Together with sunscreen, barrier lipids and corneocytes, Melanin absorbs UV energy to shield your nucleated cells. Unfortunately, a consequence of this is that excited melanin fragments yield high energy intermediates, which are known to degrade thermally and produce excited triplet-state carbonyls. Some of these triple-state carbonyls transfer energy to DNA, which ends up causing DNA damage. ⁠⠀

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What the heck does that mean?⁠⠀

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That means that even though your sunscreen shields you from direct DNA damage and immediate redness (things that SPF measures), it can't shield your skin from the indirect damage that happens hours later. That's when multiple antioxidants come in and bounce around excited energy until it finally gets quenched. Read more about how this happens in our encyclopedia entry on Acetyl Zingerone.⠀Ok, enough geeking out about UV.

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Picking / Scratching

This one’s pretty obvious: picking and scratching can cause physical damage (literally destroying or disrupting parts of the skin barrier). Even without piercing the skin, the inflammation these actions can cause

Irritant Exposure

What irritates your skin varies highly from person to person. We don’t particularly like “no lists” or telling people what to avoid, but here are the most common skin irritants. If you find that skincare products are irritating your skin, look here first:

  • Surfactants: SLS, SDS
  • Fragrances: Citrus
  • Preservatives: Sodium Benzoate
  • Essential Oils: Citrus
  • Botanical Extracts: Yarrow
  • Actives: Tretinoin

Note: we’re not saying to avoid these. For some, even the strongest irritants may not affect your skin if you have a strong penetration barrier. For others, even mild ingredients that wouldn’t appear on a list like the above can become irritant. It’s one of the reasons that when it comes to skin, your milage may vary (YMMV) is an important principle.

Harsh Environments

Extreme temperatures (and rapid temperature changes) can inflame the skin, inhibit or delay barrier function, and make skin more prone to damage from irritants like those discussed above.

Humidity also plays a fairly obvious role: dry environments (under 40% relative humidity) can cause dry, itchy, irritated skin and lead to barrier damage. Humid environments (>60% relative humidity), can on the other hand lead to inhibited filaggrin degradation (which means fewer Natural Moisturizing Factors available to the skin) and decreased barrier repair.

Pollution

Recently, we’re reading more and more papers highlighting the effects of pollution, notably Polycyclic Aromatic Hydrocarbons (PAHs), on the skin. Should you be worried? Probably not so much as long as you wash your face and use antioxidant serums. This is more for those who have high exposure to urban dust: people in industrial manufacturing, people who work outside in urban areas, coal miners, etc.⁠

(Poor) Skincare

  • Overwashing can dehydrate skin and increase its permeability, making skin more prone to irritation (and thus barrier damage)
  • Overexfoliating using acids that are too strong, or using acids too frequently (more than every other day at most) can throw off the skin’s pH and cause barrier damage or even hyperpigmentation.
  • Occlusion applied alone, occlusives can delay barrier repair compared to not applying anything on the skin. We can see under electron microscopes that it can cause swiss-cheese holes in the skin, which prevents access to barrier repair enzymes. However, applied together with barrier lipids, it accelerates barrier repair. ⁠⠀

Stress

Yes, it may stress you out to know that stress isn’t good for your skin barrier. Stress inhibits barrier repair, amongst other effects.

Reducing these sources of barrier damage is the first step.

Step Two: Boost the barrier

Skincare products best help the barrier by boosting the very components of the barrier present naturally in our skin.

  • Corneocytes: Retinoids, Hydration Serums, Acids
  • Barrier Lipids: Ceramides, Cholesterol, Fatty Acids
  • Natural Moisturizing Factors (NMF): NMFs and other humectants
  • Acid Mantle: Acids
  • TJ & Desmosomes: Osmolytes (Taurine, Myoinositol, Betaine), Sunscreen
  • Aquaporins: Niacinimide, Retinoids, Glyceryl Glucoside, Isosorbide Dicaprylate
  • Serine Protease: Tranexamic Acid

Step Three: Reduce inflammation and use barrier repair products

We’ve established that inflammation is a key barrier towards barrier repair (pun intended!). For severe cases of inflammation, topical steroids are often employed, but we must remember that these typically reduce the inflammation, not necessarily the source of barrier damage. Stop using the steroid, and the inflammation can return.

Fortunately, non-steroidal anti-inflammatory agents (NSAIDs) can help reduce inflammation and also help address some of the root causes of barrier damage.

It’s important to use anti-inflammatory agents and apply barrier repair products. Wave Serum, Level Serum and C.R.E.A.M. are all formulated to help out in their own respective ways.

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