Ceramides are lipids that fill the spaces between cells in the stratum corneum. They make up about 50% of total stratum corneum lipids and act as the "cement" of the skin barrier.
When ceramides run low, gaps form in the barrier — as if the cement between bricks were missing — letting moisture escape and irritants penetrate.
Types of ceramides — differences by number
Skin contains many ceramide types, from 1 to 12. The main ceramides that frequently appear in skincare products are:
| Type | Role | Notes |
|---|---|---|
| Ceramide 1 (EOS) | Maintains barrier structure, prevents water loss | Especially important for atopic/dry skin |
| Ceramide 3 (NP) | Maintains hydration, elasticity | The most commonly used |
| Ceramide 6-II (AP) | Normalizes desquamation | Promotes stratum corneum renewal |
Products containing all three together work better for barrier recovery than a single ceramide. Dermatology research suggests a 3:1:1 ratio of ceramides 1·3·6-II + cholesterol + fatty acids is optimal for barrier recovery.
Why ceramides become depleted
Skin ceramide content naturally declines with age. Research suggests people in their 40s have about 30% less ceramide than those in their 20s.
External factors that deplete ceramides:
- Cleansers with strong surfactants
- Hot-water washing
- Frequent exfoliation
- Dry environments (heating, AC)
- UV exposure
- Aging
How to choose ceramide products
Keywords to look for in the ingredient list:
- Ceramide NP, Ceramide AP, Ceramide EOP
- Ceramide 1, 3, 6-II
- Phytosphingosine, Sphingosine (ceramide precursors)
Synergistic ingredients to look for alongside:
- Cholesterol: one of the three barrier lipids alongside ceramides
- Fatty acids: linoleic acid, stearic acid
- Hyaluronic acid: pulls in moisture while ceramides prevent loss
- Niacinamide: promotes the skin's own ceramide synthesis
Ceramide vs other moisturizing ingredients
| Ingredient | Main function | Notes |
|---|---|---|
| Ceramide | Restores barrier structure | Fundamental barrier strengthening |
| Hyaluronic acid | Pulls in moisture | Immediate hydration |
| Glycerin | Holds in moisture | Versatile, safe |
| Squalane | Supplies lipids, protects barrier | Light oily feel |
| Panthenol | Cell renewal, soothing | Supports barrier recovery |
Rather than using ceramides alone, combining hyaluronic acid to supply moisture with ceramides to seal the barrier is more effective.
Using ceramides by skin type
Dry/atopic skin: Apply ceramide cream thickly as the last evening step. Prioritize ceramide 1·3·6 complex formulas.
Oily/acne-prone skin: A light ceramide lotion or gel cream. A ceramide + niacinamide combo also helps with sebum control.
Sensitive skin: Fragrance-free ceramide products. Using them with madecassoside or panthenol adds soothing benefits.
Aging skin (40s+): Ceramide + retinol together (retinol at night, ceramide AM/PM). Ceramides cushion early retinol irritation.
SKINROUTE and ceramide care
If your SKINROUTE SKIN100 barrier indicator comes out low, it's a sign you need focused ceramide care. Your AI coach recommends the ceramide product form and application order best suited to your current skin condition.