Skin Function – The Epidermis (Part 2)

Within the epidermis lies the stratum corneum, a vital layer often referred to as the skin’s barrier zone. This protective shield plays a key role in keeping harmful bacteria and chemicals from penetrating the skin—even after they pass through the surface sebum layer.

Unfortunately, some cosmetics and cleansers contain synthetic surfactants that can damage this barrier. When disrupted, the skin becomes more susceptible to harmful substances reaching deeper layers, which can lead to long-term skin issues.

The barrier’s defense system is powered by two main types of lipids. About 90% is made up of triglycerides and squalene—natural oils secreted from the sebaceous glands to form a protective film on the skin. The remaining 10% includes ceramides and cholesterol, which fill the spaces between skin cells in the stratum corneum.

These intercellular lipids are essential for locking in moisture and maintaining the skin’s defense function. Strong, healthy skin starts with a strong barrier—and these natural components are the key.