Transepidermal water loss (TEWL) refers to the continuous diffusion of water from the deeper layers of your skin through the epidermis (outermost layer) in the surrounding atmosphere. It is a natural process that happens in our skin to regulate hydration levels. However, excessive TEWL can lead to very dry skin.

Shop Dewy Hydrating Hybrid Sunscreen

In this article, we will understand what causes TEWL, how it can be prevented, ingredients that can help you combat it, and more.

TEWL meaning

Did you know that around 60% of the human body is made up of a lot of water? Water is very important for our bodies to work properly. It helps control the body temperature, removal of waste, and keeping your joints lubricated.

TEWL essentially signifies the amount of water that passes from beneath the skin through the epidermal layers to the surrounding environment. It is measured in grams per square meter per hour (g/m2/h).

Transepidermal water loss (TEWL) is when water evaporates from our skin into the air. Some water loss is normal, but too much can cause problems. When TEWL is higher than normal for a short time, skin can look dull, less firm, and feel tightly stretched. This is like when you get dehydrated.

But ongoing high TEWL can mean the skin barrier is damaged. Signs of this include red, itchy, and flaky skin. Over time, high TEWL may make your skin look very dull. High TEWL can be both a cause and result of skin barrier problems. So it can start a cycle - damage causing more water loss, and more water loss would cause more damage to your skin.

Did you know that the topmost layer of our epidermis is known as stratum corneum? This layer acts as the main barrier that can prevent excess water loss from your inner skin layers. Ideally, some amount of TEWL is essential to maintain a normal balance of hydration in your body.

However, when the function of the stratum corneum barrier gets compromised due to some reasons, it leads to very high TEWL causing your skin to become excessively dry.

What causes transepidermal water loss?

There can be several causes leading to abnormally high TEWL. Notable reasons include the following:

Harsh Weather

Extreme cold, dry or hot weather conditions tend to disrupt the integrity of your stratum corneum. It can cause increased TEWL and evaporation of water from your skin.

Using Drying Skin Care Products

Many skin cleansers and products contain sulfates and alcohols which damage the skin barrier leading to dehydration and irritation. You could consider using The Pink Foundry's Waterlight Gel Moisturiser for soft, supple, and hydrated skin.

Over-washing

Frequent cleansing without replenishing the moisture content can deplete the protective oils from your skin. This can disturb the barrier function performed by the outermost layer of your skin.

Excessive Sun exposure

UV radiation from the sun can damage the lipids and proteins of the stratum corneum (outermost layer). It can cause skin inflammation and increased TEWL.

Also read: 6 Ways to Protect your Skin from Sun Damage

Skin conditions

Eczema, psoriasis, and other inflammatory skin conditions can damage your skin's barrier layer. This could lead to severely increased TEWL.

How to prevent TEWL?

Here are some tips to strengthen your skin barrier function and prevent excessive transepidermal water loss:

• Limit cleansing to twice a day. Use gentle cleansers without sulfates or alcohols.

• Apply a hydrating toner after cleansing to replenish your skin's moisture. Hyaluronic acid and glycerin usually work wonderfully.

• Use mild exfoliators like lactic acid and polyhydroxy acids (PHAs) which can help you remove dead cells gently without irritation.

• Always wear sunscreen when stepping out to limit the UV damage. Choose mineral options over the chemical ones. You could consider using The Pink Foundry's Dewy Hydrating Hybrid Sunscreen SPF 50+ to protect your skin from UV-A and UV-B radiations with new-gen filters.

• Moisturise at least twice a day with products containing skin-friendly ingredients like ceramides, cholesterol and fatty acids.

• Incorporate antioxidant serums containing vitamin C and vitamin E to combat free radical damage.

• Use a humidifier during dry weather to add moisture back into the environment.

Best ingredients for transepidermal water loss

Using products with the right ingredients can greatly help strengthen your skin's barrier function and prevent excess TEWL. Some of the best ingredients to look for include:

1. Ceramides

Skin ceramides are lipids that help form the mortar structure between your skin cells. They can get depleted with time, causing cracks in your skin's barrier layer. This can lead to water loss. Applying creams with ceramides can help you mimic your skin's natural lipids and repair the barrier layer.

2. Hyaluronic acid

Hyaluronic acis is a powerhouse ingredient. It has an exceptional ability to hold water and hydrate your skin layers. It pulls moisture from the environment and brings it into the skin. It is effective in preventing TEWL.

Also read: What is Hyaluronic Acid?

3. Occlusives

Occlusives are the ingredients that sit on the top of your skin and act like a shield to prevent moisture loss. Some great natural occlusives are beeswax, shea butter and oils like almond, olive and coconut oil.

4. Colloidal oatmeal

Oatmeal is rich in lipids, proteins and beta-glucan that can help you repair your skin's natural moisture barrier. It can work on inflammation caused disruptions. It forms a protective film that could help you limit TEWL.

5. Niacinamide

Also known as vitamin B3, niacinamide can help you boost your skin's ceramide production. This can help you reinforce the dermal barriers weakened by external factors. Weakened dermal barriers lead to higher water evaporation resulting in dryness.

Also read: What is Niacinamide?

Conclusion

Moderate TEWL is a normal process essential for your skin's health and hydration balance. However, increased TEWL due to skin barrier damage can cause bothersome dryness and irritation. Following skin care best practices like using gentle cleansers, replenishing the moisture after cleansing, applying sunscreen, and using targeted ingredients like ceramides can help you reinforce skin's barrier function. These measures can help you protect your skin from excess water loss and keep your skin soft, supple and hydrated.