What is Transepidermal Water Loss and Why is it Important?

What is Transepidermal Water Loss and Why is it Important?

Do you ever find your skin feeling ridiculously dry? How about seeing those pronounced wrinkles and fine lines first thing in the morning? Is your skin crepey? All are results of a process that occurs naturally called TEWL, otherwise known as Transepidermal Water Loss.

The official definition is: Transepidermal water loss (TEWL) is the amount of water that passively evaporates through skin to the external environment due to water vapor pressure gradient on both sides of the skin barrier and is used to characterize skin barrier function. (Sciencedirect.com)

In layman’s terms, it’s the water that your skin loses through its surface. Circumstances such as diet choices, low-humidity weather conditions, injury and topically applied products that dry out the skin can all impact TEWL. Although it is a natural process, TEWL can contribute to a variety of dry skin conditions. But there are ways that you can help your skin stay moisturized and hydrated.

The skin is comprised of three primary layers: the epidermis, the outermost layer; the dermis or middle layer; and the hypodermis, the undermost layer. When water passes from the dermis through the epidermis and evaporates from the skin’s surface, this is known as transepidermal water loss (International Journal of Pharmaceutics). TEWL is a natural process that your skin uses to regulate itself, but multiple factors can damage the skin’s barrier functions which ultimately affect TEWL levels.

The importance of hydration and skin moisturization are key in maintaining desirable levels of TEWL and minimizing the accelerated aging of skin. Hydration refers to the water content of the skin, whereas moisturization is the skin’s ability to retain those water molecules. You need both: hydration and moisturization for optimal skin health. Try maintaining a complete approach to skin anti-aging by using skincare products that contain effective moisturizing ingredients that won’t cause irritation or dryness.

When researching skin care products, choose moisturizers and serums that combine humectant and occlusive ingredients such as Hyaluronic Acid. Humectants help to draw moisture from the air to the epidermis if it is humid enough, or from the underlying dermis in low-humidity conditions. The occlusive agents simultaneously keep pollutants, toxins and harmful bacteria out. Together you have a powerhouse of protection for your skin. They create a reservoir of moisture in the epidermis and act as a barrier on the skin to help prevent TEWL by sealing in that moisture.


Kakadu Plum Antiox-C Serum.

One of our favorite haia products featuring hyaluronic acid to combat TEWL is the Kakadu Plum Antiox-C Serum.

Remember, skin loves consistency, so use them regularly and experience a smoother more radiant complexion.

Written by Jennifer Sposato

Jennifer Sposato

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