What is TEWL?
Our skin serves as the body’s largest and most multifunctional organ, acting as a protective barrier, a regulatory system, and a sensory interface with the world. Its primary function is to shield the body from environmental threats like bacteria, UV rays, toxins, and physical injury. It helps regulate body temperature through sweat and blood flow, and it supports immune defense by signaling the presence of harmful agents. Our skin also plays a crucial role in maintaining hydration by preventing excessive water loss through its lipid-rich barrier.
The skin barrier is the outermost layer of skin and plays a vital role in maintaining overall health. Made up of tightly packed skin cells, or corneocytes, held together by a matrix of lipids—including ceramides, cholesterol, and fatty acids—it functions like a protective shield. This barrier blocks harmful environmental aggressors like bacteria, pollutants, and irritants while keeping skin hydrated by helping to prevent moisture loss.
Transepidermal water loss (TEWL) is the natural process by which water evaporates from the skin’s surface into the surrounding environment. While a small amount of this water loss is normal and expected, excessive TEWL indicates a compromised skin barrier and can lead to dryness, irritation, and sensitivity. Factors such as cold weather, low humidity and harsh skincare products can increase moisture loss. When the skin's outer layer—especially the lipid matrix—is damaged, it becomes less effective at holding in moisture.
To help prevent excessive and damaging transepidermal water loss (TEWL) we must support and strengthen the skin barrier with a thoughtful skincare routine. For our brand, this means using a daily pH balanced cleanser and hydrator that is gentle and won’t disrupt the skin’s lipid bilayer along with an effective weekly exfoliant.
When shifting your routine to include a lipid-based hydrator, we recommend starting out with either our Lavender & Primrose Moisturizer or Chamomile Infused Moisturizer. They are formulated with ceramides, humectants and probiotics, they absorb quickly and provide an occlusive barrier on skin to seal in moisture. After 2 to 3 months of use you will find that skin is more accepting of hydration and better able to retain it. At that time you can shift your routine to include our Evening Rose Facial Serum as your twice daily hydrator, as it is fully concentrated, lightweight and rich in vitamin C for even greater skin benefits.