What the skin barrier really is
The skin barrier relies on the precise arrangement of two components: keratinocytes and intercellular lipids. These lipids—ceramides, cholesterol, and fatty acids—form alternating layers that hold the structure together, much like the bricks and mortar of a biological wall.
When this structure is intact, the skin retains moisture, blocks irritants, and resists damage. When it breaks down, the aging process accelerates, and the skin loses its density, radiance, and resilience.
This isn't a metaphor; it's a measurable biological mechanism.