transepidermal water loss twel dry skin

Everything You Need to Know About Transepidermal Water Loss (TEWL) and How to Prevent It

Old Boy

By in Health

If your skin often feels dry, flaky, or even irritated, it may not just be “dry skin.” The issue could be something called transepidermal water loss, or TEWL. TEWL is a fancy way of describing the process where water evaporates from your skin, leaving it dehydrated and vulnerable. Here we break down what TEWL is, why it matters, and, most importantly, how to prevent it to keep your skin healthy, hydrated, and resilient.

What is Transepidermal Water Loss (TEWL)?

Understanding TEWL

TEWL, or transepidermal water loss, happens when water passes from the deeper layers of your skin, known as the dermis, up through the epidermis and then evaporates from the skin’s surface. This natural process helps regulate skin hydration, but too much water loss can weaken your skin’s barrier, leading to dryness, sensitivity, and even premature aging.

Why Does TEWL Matter for Skin Health?

The skin’s barrier—often called the lipid barrier or moisture barrier—plays a crucial role in preventing TEWL. This barrier is like a wall of bricks (skin cells) held together by “mortar” (lipids like ceramides, fatty acids, and cholesterol). When this barrier is intact, it prevents excess water from escaping. But when the barrier is compromised, more water escapes, increasing TEWL and leading to dryness and irritation.

What Causes Transepidermal Water Loss?

Environmental Factors

Environmental conditions like low humidity, wind, and sun exposure can speed up TEWL. Dry, cold climates are especially harsh, as low humidity pulls moisture from the skin, leading to more significant water loss. UV radiation from the sun can also damage the skin’s barrier, making it harder for skin to retain moisture.

Skincare Routines and Products

Some skincare habits can unintentionally increase TEWL. Harsh cleansers, over-exfoliating, and using high-pH products can strip the skin of its natural oils and disrupt the moisture barrier. Ingredients like alcohol can also dry out the skin and lead to excessive water loss.

Age and Lifestyle

As we age, our skin naturally produces fewer lipids, making it more prone to TEWL. Lifestyle factors, like a diet lacking in essential fatty acids or not drinking enough water, can also affect how well your skin retains moisture. Certain health conditions, like eczema and psoriasis, can also increase TEWL due to compromised skin barriers.

Signs Your Skin is Experiencing High TEWL

Common Indicators

How do you know if TEWL is affecting your skin? Here are some signs to watch for:

  • Dryness and Flakiness: If your skin constantly feels tight, dry, or rough, it could be due to increased water loss.
  • Increased Sensitivity: When your barrier is compromised, your skin becomes more sensitive to irritants, leading to redness or stinging sensations.
  • Loss of Firmness: Dehydrated skin often appears less firm and plump, making fine lines and wrinkles more noticeable.
  • Chronic Irritation: Persistent itching or a burning sensation can be a sign that your skin is struggling to retain moisture.

How to Prevent TEWL and Lock in Moisture

Use Barrier-Repairing Ingredients

Ingredients like ceramides, fatty acids, and cholesterol are essential for maintaining a strong skin barrier. Look for moisturizers containing these ingredients, as they replenish the natural “mortar” between skin cells, reducing water loss. Think of ceramides as the glue that keeps your skin cells tightly packed and resilient.

Incorporate Humectants into Your Routine

Humectants are ingredients that attract water to the skin. Hyaluronic acid, glycerin, and aloe vera are popular humectants that draw moisture into the upper layers of your skin. Use a serum with humectants and layer it under a moisturizer to lock in hydration.

Choose Occlusives to Seal in Moisture

Occlusives are ingredients that form a protective layer on the skin, helping to prevent moisture from evaporating. Common occlusives include petrolatum, lanolin, and shea butter. After applying a moisturizer with humectants, add an occlusive layer to create a seal and prevent TEWL.

Creating a Routine to Minimize TEWL

Maintaining a consistent skincare routine focused on hydration and barrier repair can help reduce TEWL. Here’s a simple guide:

  • Step 1: Gentle Cleanser – Choose a hydrating, sulfate-free cleanser that won’t strip your skin of its natural oils.
  • Step 2: Hydrating Serum – Apply a serum with hyaluronic acid or glycerin to attract moisture to the skin.
  • Step 3: Barrier-Repairing Moisturizer – Use a moisturizer rich in ceramides and fatty acids to strengthen your skin’s barrier.
  • Step 4: Occlusive Layer (Nighttime) – At night, add an occlusive product, like a balm or thicker cream, to lock in moisture.

Additional Tips for Reducing TEWL

In addition to your skincare routine, consider these tips to further reduce TEWL:

  • Avoid Hot Showers: Hot water can strip your skin’s natural oils. Opt for lukewarm showers and avoid prolonged exposure to water.
  • Use a Humidifier: If you live in a dry climate, a humidifier can help maintain moisture levels in the air, which can be beneficial for your skin.
  • Stay Hydrated: Drinking water won’t directly affect TEWL, but it helps keep your skin cells hydrated from the inside out.

Key Ingredients to Look For (and Avoid) in TEWL Prevention

Ingredients That Help Prevent TEWL

Certain ingredients are particularly effective at reinforcing the skin barrier and reducing TEWL. These include:

  • Ceramides: Reinforces the skin’s barrier, making it harder for water to escape.
  • Hyaluronic Acid: A humectant that draws moisture into the skin, keeping it hydrated.
  • Shea Butter: An occlusive that forms a protective layer on the skin, sealing in moisture.
  • Niacinamide: Also known as Vitamin B3, this ingredient boosts barrier function and soothes irritation.

Ingredients That Increase TEWL

On the other hand, certain ingredients can disrupt the skin’s barrier and worsen TEWL. Here are a few to be cautious of:

  • Alcohol (denatured or SD): Often found in toners, it can dry out the skin and weaken the barrier.
  • Harsh Exfoliants: Over-exfoliating with ingredients like glycolic acid or scrubs can disrupt the barrier, leading to increased TEWL.
  • Sulfates: These harsh cleansing agents can strip the skin of its natural oils, increasing water loss.

The Long-Term Benefits of Managing TEWL

By focusing on reducing TEWL, you’re not only keeping your skin hydrated in the short term but also setting it up for long-term health. Proper hydration supports elasticity, minimizes signs of aging, and keeps your skin barrier strong. When your skin can retain moisture, it becomes more resilient, plumper, and naturally radiant. Remember, hydrated skin is healthy skin, and managing TEWL is a critical step in achieving that balance.