Skin Barrier

Bonus region

How does the skin Barrier work?

The outermost layer (stratum corneum) is like a brick wall: flattened dead cells as bricks, fats as mortar.

The mortar

Ceramides, cholesterol and fatty acids keep water in and irritants out.

Disruption

Harsh cleansing, very hot water and some conditions damage the barrier; moisturizers help repair it.

Evidence & sources

• The outermost skin layer, the stratum corneum, is the main barrier against water loss. Evidence: established. Known: Basic skin physiology. Unknown: — Source: NCBI Bookshelf (StatPearls), Physiology, Integument (Current revision).

Connected topics

• Moisturizer
• Soap & Cleansers
• Glycerin
• Petrolatum
• UV Radiation

Try it in your browser

General education only, not medical advice. Drafted Oct 2026 · pending qualified expert review.