You hear the term ‘skin barrier’ everywhere these days… but what is it actually?

It’s the outermost layer of your skin — and no, it’s not just a trendy word. It’s basic biology (term that goes back to 1999).
Your skin is built like a wall. In humans, we often describe it as “brick and mortar”: the cells (called corneocytes) are the bricks, and the mortar is a mix of lipids — ceramides, cholesterol, and fatty acids — that hold everything together and keep it strong.

(Fun fact: in birds 🐦, it’s more like 'straw and mortar'. In aquatic mammals, it’s 'plates and mortar'.)

Anyway, back to humans.
This barrier is your first line of defense. It keeps out bacteria, allergens, and pollution, and it holds moisture in. So taking care of it isn’t just about glowing skin or anti-aging — it’s about basic health.

 

How do I build a stronger skin barrier?

You replenish it with the same stuff it’s made of: ceramides, cholesterol, and fatty acids.

You’ve probably heard of the 12-step Korean skincare routine, but honestly? For skin health, only three steps really matter:

 

1. Cleansing (but do it your way)

Some dermatologists recommend washing your face or showering only once a day. But let’s be real — if you're active, live in a city, or sweat even a little, that advice makes no sense. You think people walking around with sweaty armpits, nasty groins, and city grime only need one wash? That’s how we lose the plot.
 

Here’s a personal plot twist:
In my teens and 20s, I tried every “pH-balanced,” “mildly acidic,” “double-foaming” cleanser that claimed to be gentle but deeply effective. None of them worked.
The only thing that actually cleaned my pores, removed makeup, and smoothed the texture around my nose and chin?
An alkaline bar soap.
Yep — the very thing I was told to avoid.
My skin finally felt clean. My makeup washed off without effort. The results were obvious.
So no, the textbook doesn’t always match real life. And just because something is “dermatologist-recommended” doesn’t mean it works for everyone. If I hadn’t stuck to the gentle stuff and had actually removed hardened sebum daily, I wouldn’t have ended up with enlarged pores.

And for the record, if I wash my face only once a day, my sebum hardens and it’s not pretty. 'Your oily skin’ and my oily skin are not the same. Mine wipes out semi-permanent eyebrow tattoos in 7 days. It was supposed to last 1-3 YEARS. I’ve tested it four times.

 

Fun fact: About 90% of the lipids (oils) on your skin’s surface come from sebum, while only around 10% are produced by your skin itself in the stratum corneum.

Sebum is especially rich in triglycerides — and here’s where it gets interesting: skin-resident microbes produce enzymes called lipases that break down those triglycerides into free fatty acids (FFAs). These FFAs help acidify the skin’s surface, creating the slightly acidic environment that’s essential for a healthy barrier and strong microbial defense.

So in hindsight? I didn’t need a specially formulated “acidic” cleanser at all — I was already producing plenty of sebum to do the job naturally.

 

2. Moisturizing (understand what you’re doing)

Moisturizers are made of three main types of ingredients:
• Humectants – pull water into the skin (think glycerin or hyaluronic acid)
• Emollients – smooth and soften by replenishing lipids (plant oils, for example)
• Occlusives – trap moisture in by forming a seal (like petroleum jelly or lanolin)

Depending on your age, climate, or skin type, you may need all three in balance — or maybe just one or two.

Most water-based moisturizers rely heavily on humectants. These are great for pulling moisture into the skin, especially in humid environments. But they don’t work alone — without the support of emollients and occlusives to seal in that moisture, it can just evaporate off your skin again (a phenomenon known as transepidermal water loss, TEWL).

That’s why layering is key: think of a water-based serum or gel to hydrate, followed by an oil or balm to lock it in.

Enter ceramides.

Ceramides are a special class of lipids that make up around 50% of your skin barrier by weight. When your barrier is damaged — whether from over-cleansing, sun exposure, or environmental stress — ceramides help rebuild it.
They’re biologically relevant, skin-identical ingredients that can help restore your barrier function and reduce moisture loss. Incorporating them into your moisturizer can be a game changer. Among the ceramides, ceramide 3 (NP) is considered the most effective in repairing skin barrier damage.

Want to know what ceramides actually are? Read here, and here.

(I almost worked with this company for proteomics project when I worked in the drug discovery industry, it’s cool that they have information on ceramides. I highly recommend checking out their posts!)

 

Oils are emollients.

 The right ones mimic the fatty acids your skin already makes. They absorb quickly, won’t clog pores, and actually strengthen your barrier instead of wrecking it.

A few examples from our facial oil:

• Jojoba Oil – Technically a wax ester, almost identical to human sebum. Helps dissolve hardened oil in pores.
• Sunflower Oil – High in linoleic acid (great for barrier repair), and proven safe even for eczema-prone skin.
• Squalane – A stable version of squalene, which your skin already produces. Lightweight, nourishing, and non-comedogenic.
• Evening Primrose Oil – Helps reduce inflammation and may ease hormonal flare-ups.
• Argan Oil – Loaded with antioxidants and vitamin E. Great for calming stressed skin.

 

And just a heads-up: the price tag doesn’t always reflect quality. There are great options at every price point — from drugstore to dermatologist's office — so don’t fall for the $100 bottle unless it’s really doing something special for your skin.

Ceramides and fatty acids are not a gimmick. Just make sure you’re getting the real deal, in a formula your skin actually likes! (Not every fatty acids are skin-identical.)

 

Here’s something cool:
A small amount of oil acts as an emollient, but, use a little more, and it becomes a light occlusive — sealing in hydration under a breathable lipid layer.

And here’s something you should avoid putting directly on your face:
• Olive oil – High in oleic acid, which can disrupt your barrier and feed Malassezia (fungal acne, causes dandruff too)
• Coconut oil – Clogs pores (comedogenic) like it’s its full-time job. Especially bad for acne-prone or combo skin. 
• Essential oils (undiluted) – These concentrated compounds can cause irritation, photosensitivity, and allergic reactions if not properly diluted.

Natural doesn’t always mean safe or the best. Know your lipids.

 

3. Sunscreen (it’s not just a “chemical”)

If you have sensitive skin, start with mineral sunscreens that contain zinc oxide or titanium dioxide. These sit on the surface of your skin and reflect UV rays, kind of like tiny shields.

Chemical sunscreens work differently. They absorb UV rays and convert them into heat. The issue? Depending on where you live, you may have limited access to better options.

• Europe and Asia allow advanced filters like Tinosorb S, Uvinul A Plus, and Mexoryl SX; these are more stable, less irritating, and work beautifully.
• The U.S.? Still waiting on FDA approval for most of those, so we’re stuck with older, more finicky filters.

I personally love sunscreens made in France, Korea, and Japan. The texture, finish are just better.

 

And for the “our ancestors didn’t use sunscreen” crowd:

First of all, your ancestors died at ~40.
Second, they didn’t destroy the ozone layer, we did. The UV exposure we get now is much more intense. So yes, wear sunscreen. Or carry a sunbrella. (Yes, it’s a thing in Korea, and it’s fabulous.)

 

Final Thought

Taking care of your skin barrier isn’t about chasing trends. It’s about understanding biology and using ingredients your skin actually recognizes.

Skip the hype. Use what works.
Your barrier will thank you.