Ceramides
Also known as: Ceramide NP, Ceramide AP, Ceramide EOP, Sphingolipids
The natural fats that glue skin cells together — replenished topically to repair a compromised barrier.
In short
Ceramides are lipid (fat) molecules that make up about half of the skin's outermost layer and act as the mortar between skin cells. They form the barrier that keeps water in and irritants out. When the barrier is damaged — by harsh cleansers, cold weather, eczema, or age — ceramide levels drop. Applying ceramide-containing moisturizers helps replenish them, reducing dryness, irritation, and water loss.
- Make up ~50% of the skin barrier's lipid mortar
- Skin naturally produces them; production declines with age
- Key forms in skincare: ceramide NP, AP, and EOP
- Strongest evidence: barrier repair, dryness, and eczema-prone skin
What is Ceramides?
Think of the stratum corneum — the skin's outermost layer — as a brick wall: skin cells are the bricks and ceramides, cholesterol, and fatty acids are the mortar. Ceramides are the dominant mortar ingredient, and without them the wall leaks water and lets irritants through. This 'leaky wall' model explains a lot: eczema-prone skin, winter dryness, and post-cleanser tightness all involve depleted ceramides. Topical ceramides replenish the mortar, which is why they anchor the most popular barrier-repair moisturizers.
Where it comes from
Natural sources
- Produced endogenously by skin cells (keratinocytes)
- Wheat germ and rice bran (plant-derived ceramides)
- Egg yolk and dairy fats (trace dietary sources)
How it's made
Skincare ceramides are bio-identical molecules produced via fermentation or synthesis, often labeled as pseudoceramides when structurally similar.
What it does in products
Benefits
Barrier repair
strong evidenceClinical studies show ceramide formulations measurably reduce water loss and improve skin barrier function, with effects confirmed by measuring TEWL and skin hydration.
Dryness and flaking
strong evidenceCeramide moisturizers restore lipids stripped by harsh cleansers and dry climates, reducing tightness and visible flaking within days to weeks.
Eczema-prone skin support
strong evidenceAtopic dermatitis involves a ceramide deficiency in the barrier. Ceramide-rich emollients are a standard adjunct in eczema care, reducing flare frequency in studies.
Tolerating active ingredients
moderate evidenceA strong barrier is the prerequisite for retinoids and acids; ceramide moisturizers are the standard companion product to prevent 'retinoid burn' and peeling.
Side effects & safety
Safety considerations
- Topical ceramides are considered safe during pregnancy and breastfeeding.
- None known — ceramides combine well with all actives and are used to buffer irritation.
- Not for: Known allergy to a specific ceramide source (rare)
How it's used
In skincare
Ceramides are effective at low percentages (typically 0.1–1% of the formula). Products combine ceramides with cholesterol and fatty acids at an optimal ratio for barrier repair. Apply after serums and actives, morning and/or night.
Regulatory status
- Cosmetic ingredient under the FD&C Act; ceramide ingredients also have GRAS status for oral use in some applications.
- GRAS (generally recognized as safe) for food use.
- INCI name on cosmetic labels: Ceramide NP / Ceramide AP / Ceramide EOP.
- The CIR Expert Panel has assessed ceramides as safe in cosmetics.
Popular products containing Ceramides
- Moisturizing Cream — The benchmark 3-ceramide formulaCeraVe · skincare
- Toleriane Double Repair Face MoisturizerLa Roche-Posay · skincare
- Ceramidin Cream — High-ceramide Korean barrier creamDr. Jart+ · skincare
Product names and brands are shown for reference and belong to their respective owners.
The optimal lipid ratio
Barrier repair is not about ceramides alone. Research (including the classic work underlying Atopalm and EpiCeram) shows the stratum corneum needs ceramides, cholesterol, and free fatty acids together — roughly in a 3:1:1 ratio. Adding ceramides without the other two lipids can actually slow barrier repair. The best barrier creams are formulated with all three, which is why the most studied products consistently include cholesterol and fatty acids alongside ceramides.
Frequently asked questions
Do ceramides work in a cleanser?
Cleansers with ceramides are less drying than harsh alternatives, but rinse-off contact time is short. For barrier repair, leave-on moisturizers with ceramides are the evidence-backed choice; a ceramide cleanser is a nice complement, not a substitute.
Can I use ceramides with retinol and acids?
Yes — this is exactly where ceramides shine. Layering a ceramide moisturizer over retinoids or exfoliants reduces dryness and peeling, and a healthy barrier helps skin tolerate actives long-term.
Are ceramides better than hyaluronic acid?
They do different jobs. Hyaluronic acid pulls water into the skin; ceramides seal the barrier so the water stays. For dry or compromised skin, the combination — humectant underneath, ceramide moisturizer on top — is more effective than either alone.
The bottom line
Ceramides are the skin barrier's native mortar, and topical ceramide formulas are among the best-evidenced tools for dryness, irritation, and eczema-prone skin. Look for products combining ceramides with cholesterol and fatty acids, and apply them as the final step over actives.
References
- Ceramides and skin function — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=ceramides+skin+barrier+repair
- Ceramide compound records. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/#query=ceramide
- Cosmetic Ingredient Review — ceramides safety assessment. Cosmetic Ingredient Review. https://www.cir-safety.org/ingredients
- Ceramides and atopic dermatitis — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=ceramides+atopic+dermatitis