TEWL stands for transepidermal water loss, the natural evaporation of water through your skin. It's a crucial marker of skin barrier health. High TEWL means compromised skin, dryness, and irritation.
If your skin constantly feels dry, tight, or irritated no matter how much moisturizer you use, TEWL might be the missing link. It’s a silent sign your barrier is crying for help.
At KarinaNYC, we specialize in treating skin conditions rooted in barrier damage, including elevated TEWL.
In this guide, you’ll learn what TEWL is, how to identify it, and what to do about it.
What Does TEWL Stand For? Understanding Water Loss In Your Skin
TEWL stands for transepidermal water loss, and it describes how much water your skin naturally loses to the air around you.
It’s not sweat. It’s not something you can see or feel. It’s a silent process that happens all day, every day.
Unlike sweating, TEWL is passive and constant. It happens when your skin barrier isn’t doing its job, like a leaky lid on a pot. And trust me, I see this in the treatment room all the time: clients who hydrate like crazy but still feel dry, flaky, or irritated. That’s TEWL at work.
We measure it clinically to understand the state of your skin barrier.
If TEWL is high, your skin isn’t retaining moisture properly, which means everything else, your serums, your actives, even your moisturizer, can’t perform the way they should.
TEWL And Your Barrier: The Link Between Dryness And Damage
When your skin loses too much water, it stops functioning like healthy skin. It looks dull. It feels rough or tight. And you become more prone to breakouts, redness, or even that weird post-shower sting.
A compromised barrier doesn’t just affect how your skin looks, it changes how it behaves. You might find yourself more reactive to products, more prone to fine lines, or in a constant state of sensitivity.
Think of TEWL like a leak in your roof. The damage might be invisible at first, but over time? It compounds.
And by the time most people come to see me, they’re dealing with layers of issues that all trace back to one thing: their barrier isn’t holding in hydration.
What’s Really Driving TEWL? 3 Factors You Need to Know
If your skin feels tight, flaky, or irritated, chances are TEWL is the hidden culprit. Transepidermal water loss isn’t random, it’s fueled by specific triggers.
Here are the three biggest factors driving TEWL, why they matter, and how to protect your skin’s barrier for lasting hydration.
1. Skin Barrier Integrity
Your skin barrier is your first line of defense, and when it’s compromised, whether from over-exfoliation, sun damage, or using the wrong actives, it can’t hold onto water.
Imagine your skin like a brick wall. The bricks are your skin cells, and the mortar that holds them together? That’s your lipids, your natural oils.
If the mortar breaks down, water seeps out. It’s that simple. The result? Dry patches, irritation, and a reactive skin cycle that’s hard to break without professional help.
2. Environmental Conditions
TEWL isn’t just about what you’re doing, it's about what your skin is exposed to. Cold air, indoor heating, air travel, city pollution… they all put stress on your barrier.
Living in New York, I see this every winter. Clients who were glowing in the fall walk in mid-January with flaking cheeks, dull skin, and tightness they can’t moisturize away.
That’s barrier degradation, often accelerated by environmental stressors like wind, UV, and pollution.
3. Skincare Habits
Yes, your products matter.
Foaming cleansers, harsh exfoliants, and skipping proper hydration steps can all spike TEWL. Especially when you're using trendy products without understanding what your skin actually needs.
And this is where I get a little opinionated, because I’ve seen the damage firsthand. You can’t just slap on a water-based gel and hope for the best.
Hydration has to be sealed in. Otherwise, you're just throwing water at a leaky bucket.
Normal vs Excessive TEWL
So, how do you know if your TEWL is out of balance?
Normal TEWL means your skin feels soft, supple, and calm. Products absorb well. You don’t feel tightness or sting.
Excessive TEWL looks like flaking, sensitivity, or that uncomfortable tight feeling even when you’re moisturized.
If your skin stings when you apply your serum or moisturizer, it’s waving a red flag: Help, I’m dehydrated and unprotected.
The Real Consequences Of Elevated TEWL On Your Skin
When your skin starts losing water faster than it can hold it, the symptoms don’t just sneak up, they stack up.
People often walk in thinking they need a “better moisturizer,” but the real issue is TEWL that’s been left unchecked.
Here’s what that can look like:
Flaky patches around the nose, chin, or cheeks, no matter how much you moisturize.
Redness and burning, especially after applying skincare.
Dull, dehydrated skin that looks tired even when you’re well-rested.
Breakouts or congestion because the skin’s barrier is too weak to defend against bacteria.
Fine lines that weren’t there last month, especially around the mouth and eyes.
Stinging or irritation from products you used to love, and now they suddenly “don’t work.”
And the worst part? You can’t product-hop your way out of this. Until you rebuild your barrier and address TEWL directly, even the best ingredients won’t do much.
The Top Worries About TEWL (And the Truth Behind Them)
Let’s clear up a few concerns, because there’s a lot of confusion out there, and misinformation that makes people panic or over-correct.
Can I Make TEWL Worse By Layering Too Many Products?
Yes. Especially if you’re missing the right products. Hydration needs to be locked in. If you apply five layers of serums but skip a lipid-rich cream or occlusive seal, that hydration just... disappears. You’re doing a lot but not seeing results. That’s frustrating, and it’s fixable.
Is Slugging Good Or Bad For TEWL?
It depends. A light occlusive layer can be magic for dehydrated or post-treatment skin.
But heavy petrolatum-based slugging every night? That can clog pores, especially if you’re acne-prone or not cleansing properly.
Know your skin type and season. Winter? Slug away. Summer? Probably not.
Why Do I Still Feel Dry After Hydrating Serums?
Because you haven’t sealed them in. Hydrators like hyaluronic acid pull water into the skin, but without a lipid barrier (think ceramides, squalane, or our favorite Serum TEWL), that water just evaporates.
It’s like pouring water into sand.
How To Rebuild A Strong Barrier And Reduce TEWL
This is where the real magic begins. Reducing TEWL isn’t about doing more, it’s about doing better. Your skin doesn’t need 12 steps. It needs the right support, in the right order, with the right ingredients.
Here’s how I help clients rebuild their barrier, and what you can start doing today:
1. Use a gentle, non-foaming cleanser
If your face feels squeaky-clean after washing, that’s a red flag. You’ve likely stripped your protective oils. Go for a creamy or milky cleanser that respects your skin’s natural pH.
Our go-to? Lait Dermo-S. It gets the job done without compromising your barrier.
2. Apply a hydrating serum (glycerin, hyaluronic acid)
Hydration always comes first, but it needs to be strategic. I love using lightweight water-binders like hyaluronic acid or glycerin immediately after cleansing.
Think of this step as giving your skin a tall drink of water.
3. Follow with a lipid-based serum or moisturizer (ceramides, squalane)
Hydration alone isn’t enough. You have to hold it in. That’s where lipids come in. They act like a sealant, locking moisture inside your skin.
Ceramides and squalane are two of my favorites because they mimic what healthy skin naturally produces.
4. Seal in hydration with a finishing product or balm
This is the step so many skip, and it makes all the difference. You need a finishing layer that reinforces the work your hydrators and moisturizers just did.
That could be something like Serum TEWL or even a soft balm if you’re dry or post-treatment.
5. Avoid over-exfoliation and incorporate barrier-repair masks
No one ever needed five types of acids in their routine.
Cut back. Simplify. And instead, work in calming, reparative masks, like Masque Biosensible or Creme Masque Vernix. These are designed to rebuild, not strip.
Ingredients That Help
If you’re scanning your labels (and I hope you are!), here’s what to look for:
Ceramides: These are the glue that keeps your skin cells together. They rebuild the “mortar” between the bricks in your skin wall, preventing water escape.
Squalane: Lightweight, non-comedogenic, and nearly identical to the oils your skin makes naturally. It’s excellent for sealing in moisture without feeling greasy.
Urea (5–10%): This underrated hero both hydrates and exfoliates gently. In the right formulation, it strengthens your barrier and improves texture.
TEWL-specific serums: Like Serum TEWL, which acts like an invisible lipid shield. These are made to reduce water loss directly and are especially helpful in cold climates, after peels, or if your skin is chronically reactive.
The bottom line? You don’t need more products, you need smarter ones. And the best results come from layering strategically, not randomly.
Biologique Recherche For TEWL: Hydration And Protection In Action
When TEWL is high, your barrier needs both hydration and lipids in perfect harmony. Here’s a routine I use personally and recommend often for clients experiencing excessive TEWL:
Step 1: Lait Dermo-S Cleanser
We always begin by protecting the barrier, not attacking it.
This gentle, non-foaming milk cleanser removes makeup and impurities without stripping essential oils. It leaves your skin feeling soft and calm, not tight and irritated.
Step 2: Lotion P50W (For Sensitive Skin)
This version of the cult-favorite P50 is a game changer. It gently exfoliates and balances your skin’s pH without disrupting your moisture barrier.
And yes, you can (and should) use it even when your skin feels dry, it actually helps your skin absorb what comes next.
Step 3: Serum Amniotique VG Or Extraits Tissulaires Or Colostrum VG
This is where we bring in hydration.
Amniotique VG is ideal for dry or normal skin in need of water-based moisture. It’s light but powerful.
Extraits Tissulaires is better for oily, congested, or combination skin that still needs hydration, without the heaviness.
Colostrum VG is your go-to for very dry or severely dehydrated skin. It delivers deep, nourishing hydration that comforts and restores even the most depleted complexions.
Pick one. You don’t need both.
Step 4: Crème Dermo-RL Or Creme Masque Vernix
Now we rebuild.
Crème Dermo-RL is rich in fatty acids and perfect for dry, lipid-depleted skin.
Creme Masque Vernix is our go-to for clients recovering from travel, weather extremes, or over-exfoliation. Inspired by the protective vernix on newborn skin, it’s deeply reparative and soothing.
Step 5: Serum TEWL
This is the hero product for barrier repair. It mimics your skin’s natural lipids and creates a breathable seal that locks in hydration. I recommend it year-round but especially in cold climates or post-procedure. It’s like putting a soft, invisible shield over your skin.
Step 6: Masque Biosensible (2x/week)
This mask is a reset button for stressed, inflamed, or overheated skin. It calms, hydrates, and reinforces the barrier. Use it after travel, facials, or anytime your skin feels off.
TEWL Is A Symptom, Not The Root - KarinaNYC Treats The Cause.
If your skin feels irritated, overworked, and endlessly thirsty, it’s not your fault. And you’re not alone. Most of the clients we treat have spent years trying to “fix” their skin with trendy actives, harsh exfoliants, or the wrong kind of hydration.
TEWL is almost always part of the puzzle, but it’s rarely the whole story.
You can’t fix a compromised barrier by throwing more products at it. You need a strategy. You need formulas that respect the biology of your skin, and a guide who knows exactly how to rebuild it from the inside out.
That’s where we come in.
Solutions From Karina Freedman:
💐 Barrier Repair Facial
A clinical treatment designed to reset and rebalance your skin barrier. Each session is built around Biologique Recherche’s customized protocols and your skin’s hydration profile. Clients often see results in just one session, and feel them even faster.
🌟 Serum TEWL
This is our go-to defense against winter, retinol recovery, and barrier fatigue. It creates a breathable lipid shield that seals in moisture, reduces inflammation, and helps your skin finally retain what you give it.
🌿 Creme Masque Vernix
Inspired by the natural vernix that protects newborn skin, this product is an instant rescue for dry, post-travel, or over-treated complexions. I use it myself when my skin is feeling fragile, and it never fails.
Whether you’re dealing with chronic dryness, seasonal sensitivity, or confusion about what’s actually working, our goal is always the same: to help you age beautifully with confidence and clarity.
Book your personalized consultation today. Because your skin deserves more than a band-aid fix. It deserves expert care rooted in real results.
