TEWL (transepidermal water loss) is the natural evaporation of water from the surface of your skin, a process dermatologists use to measure barrier health.

Diagram illustrating transepidermal water loss (TEWL) through the skin barrier during cooler fall weather

Switch from foaming cleansers to cream or milk cleansers that cleanse without stripping lipids.

Choose a slightly richer moisturizer than summer — but not occlusive-heavy unless needed.

Cozy fall skincare ritual scene with knit blanket, herbal tea, candlelight, and hydrating serum on bedside table
A softer season calls for softer layers.