Skin Care
If your skin feels dry or dehydrated, one reason may be transepidermal water loss (TEWL). In plain terms: your skin is losing water and moisture. TEWL can cause various dry skin problems — even severe dehydration — but there are things you can do to keep your skin hydrated or prevent dryness altogether.
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What Is Transepidermal Water Loss?
What Triggers TEWL?
How To Prevent TEWL
What Is Transepidermal Water Loss?
To understand TEWL, let’s look at the skin’s layers. The skin has three main layers: the epidermis (the outer layer you see), the dermis (middle), and the hypodermis (innermost). TEWL happens when water moves from the dermis, through the epidermis, and evaporates through the skin barrier.
As dermatologist Anna Guanche explains: “The skin barrier is the epidermis, especially the outermost layer called the stratum corneum. The epidermis itself has five layers, and the stratum corneum is the very outer one.”
When the stratum corneum is damaged, moisture escapes through a weakened barrier, leaving skin dry, dull, or dehydrated. Normally the skin can manage water loss on its own, but certain factors can harm the barrier and make dryness worse. Common signs of TEWL include:
– Irritation: A damaged barrier often feels irritated.
– Flaking: The top layer dries, dies, and flakes off.
– Itchiness: Cracks from water loss can make skin feel itchy.
– Tightness: Dehydrated cells pull together, causing tightness.
What Triggers Transepidermal Water Loss?
TEWL can be caused by:
– Skin conditions like eczema, dermatitis, or rosacea
– Dry weather or spending a lot of time in dry indoor air (from air conditioning or central heating)
– Over-washing, over-exfoliating, or using harsh soaps
– Allergies, diabetes, or kidney disease
– Aging, since sebum (skin oil) production drops
– Sunburn or wounds
– Chlorine exposure
How To Prevent Transepidermal Water Loss
The key to preventing TEWL is keeping your skin barrier healthy. A good skin barrier keeps irritants out and locks moisture and natural oils in. When it’s damaged, water escapes more easily and skin can become dry or develop conditions like dermatitis. Try these lifestyle and skincare tips to protect your skin:
1. Use Moisturizing Products
Moisturizing helps repair and maintain the skin barrier. Rich creams can lock in moisture and prevent water loss, especially overnight. Night creams are useful because skin repairs itself while you sleep, so thicker formulas with active ingredients can boost hydration and restore skin — this is particularly helpful for mature skin.
Products in our Marine Peptide Collection are formulated to reduce TEWL and lock in moisture. Some include exopolysaccharide, which helps limit water loss and improve hydration. The ultra-rich Monoi Age Corrective Night Cream for Face & Neck also helps protect and hydrate while you sleep, using tropical monoi to firm and moisturize. Watch our Lead Skin Care Trainer, Natalie Pergar, for a night routine focused on hydration.
To reduce TEWL, look for moisturizers with humectants, occlusives, and emollients. Humectants (like glycerin and hyaluronic acid) draw water into the skin. Occlusives (like beeswax) form a barrier to stop that moisture from evaporating. Emollients help smooth the skin and also reduce water loss.
2. Use a Humidifier if Your Skin Barrier Is Compromised
If you live in a dry climate or get dry skin in winter, try using a humidifier at home. Studies show humidifiers that produce very fine water particles can improve skin hydration and help the skin barrier recover.
3. Hydration Tips for Bathing
If your skin is already dry, try applying a warm, wet cloth to the face, or soak hands and feet in a basin for about 10 minutes in warm (not hot) water. After bathing, apply an occlusive moisturizer to lock in moisture.
4. Avoid Harsh Cleansers and Over-Exfoliating
Over-washing, too much exfoliation, harsh cleansers, and some acne treatments can damage the skin barrier and trigger dryness. If you’re unsure what’s causing your symptoms, see a dermatologist. As a rule, avoid over-cleansing and foaming cleansers that strip oils — a gentle milk cleanser is usually safer. Be cautious with active ingredients like retinol and alpha hydroxy acids, which can worsen TEWL for some people.
Are you dealing with TEWL? Explore the Marine Peptide Collection designed to reduce water loss and lock in moisture.