Skin Barrier
Skin Barrier (Stratum Corneum)
Definition (cosmetic use): The outermost skin layer that moderates water loss (TEWL) and surface comfort. In cosmetic science, “barrier” refers to the structure of corneocytes (“bricks”) and intercellular lipids (“mortar”)—ceramides, cholesterol, and fatty acids—along with a mildly acidic pH often called the acid mantle.
How the barrier works (cosmetic context)
- Brick & mortar: Cornified cells are embedded in lipids that influence feel, flexibility, and water retention.
- Water management: Balanced hydration reduces the feeling of tightness; excess loss shows up as dullness or a rough look.
- pH environment: A mildly acidic surface supports routine comfort and elegant layering.
- Balance, not occlusion: Lightweight lipids help preserve comfort without heavy films.
Layering & Compatibility
- AM: Hydrate (water phase) → peptide/antioxidant serum → light lipid finish → sunscreen.
- PM: Gentle cleanse → peptide/treatment serums → lipid finish for overnight comfort.
- Exfoliation: Favor calibrated frequency (e.g., AHAs + PHAs) to keep the surface smooth while preserving comfort.
Used in OUMERE
- Oil Dissolution Theory — removes residue while respecting the lipid feel.
- UV-R — water-phase hydration and botanical support (AM).
- UV-R Concentrate — nightly hydration and composure (PM).
- Serum Bioluminelle — dual-phase finish to seal hydration without heaviness.
- Serum Bioluminelle Concentrate — concentrated lipid finish for overnight comfort.
- No. 9 — calibrated AHA/PHA renewal to keep the surface refined.
See Also
Guides
Scientific Note: OUMERE definitions are cosmetic-science references for educational context and routine design. They are not medical advice.