Trans Epidermal Water Loss

I have mentioned briefly, in a previous blog post, trans epidermal water loss (TEWL) as it pertains to the skin barrier function. However, as it is a normal function of the skin that occurs for everyone it is important to understand what it is and how to prevent excess TEWL. 


Trans epidermal water loss (TEWL) is the process by which water evaporates from the skin's surface into the surrounding environment. This occurs naturally as a result of the skin's permeability, which allows water molecules to pass through the epidermis (outermost layer of the skin) and into the air. It helps to regulate body temperature and maintain hydration levels in the skin. However, excessive TEWL can lead to dehydration and dryness, which can cause a range of skin problems such as itching, flakiness, inflammation and premature aging. Over time, chronic TEWL can lead to a damaged skin barrier and worsen conditions like eczema and psoriasis.


Several factors can contribute to increased TEWL, including environmental factors like low humidity, high temperature, and wind, as well as personal factors such as skin type, age, and certain skin conditions. In addition, some skincare habits and ingredients can cause TEWL. 


  • Cleansers or Toners that contain high percentages sulfates, alcohols or astringent ingredients (i.e. witch hazel) will strip the skin of its natural protective oils and dry out the skin.  
  • Overuse of exfoliants, both physical and chemical can over-dry the skin. Maximum 3x a week for an exfoliant.
  • Taking HOT HOT showers (I am guilty of this one) and cleansing with hot water will remove your skin’s natural oils and increase TEWL. Try using tepid or lukewarm water for cleansing and apply moisturizer on your damp skin quickly, once you are out of the shower. 


To help reduce TEWL and improve our moisture levels we will want to incorporate a few key ingredients in our skincare routine. 


  • Hyaluronic Acid: attracts and holds onto moisture to help keep skin hydrated and plump. Needs to be applied onto damp skin and then a moisturizer placed on top.
    • NUDA Hyaluronic Self Tanning Serum
    • Strawberry Rhubarb Hyaluronic Hydrator


  • Lactic Acid or Glycolic Acid: act as humectants that pull water to the skin, they will also increase the skin’s own natural hyaluronic acid
    • Mangosteen Daily Resurfacing Concentrate
    • Firm Skin Acai Exfoliating Peel (acne-safe) 


  • Ceramides: lipid molecules that create a protective barrier to lock in moisture and keep out harmful pollutants and irritants. 
    • Cornflower Recovery Serum (acne-safe)
    • Tizo AM Replenish SPF 40 (acne-safe)


  • Niacinamide: a form of vitamin B3 that helps with cell repair, improvement of moisture retention and reducing inflammation
    • Birch Water Purifying Essence (acne-safe)
    • Acne Advanced Clarifying Hydrator


  • Vitamin C: increases the skin’s density via increasing collagen protein. Denser skin will have less water evaporating. 
    • Vitamin C Antioxidant Serum (acne-safe)
    • Superfood Booster Powder


  • Facial Oils: these will contain natural fatty acids that will act as an occlusive barrier preventing water from evaporating. I always apply oils after my moisturizer, and before my sunscreen, to seal everything in. 
    • Facial Recovery Oil (acne-safe)
    • Camellia Glow Solid Face Oil


As we all experience TEWL to some degree it is important we are aware of what we are applying to our skin. Keeping TEWL at a minimum is crucial for improving our hydration levels and maintaining a healthy skin barrier.  

-Blog by Stephanie Byrne