Dr Tiina Meder explains trans-epidermal water loss in Stylist.

“In healthy skin, TEWL is always proportional to skin hydration. The problems start when the ratio of TEWL is inverted, skin hydration is decreased and TEWL increased,” explains Dr Tiina Meder, GetHarley dermatologist and founder of Meder Beauty. “Extremely cold or extremely hot air will increase TEWL, as will smoking, air pollution or ultraviolet radiation. Another important trigger is stress; the key stress hormone, cortisol, influences the skin lipids production, hyaluronic acid balance and many other processes which lead to skin barrier damage and therefore increases TEWL”.

Read the full article in Stylist