Good evidence
Ceramides
INCI: Ceramide NP, Ceramide AP, Ceramide EOP · also skin ceramides, sphingolipids, Ceramide 3, 6-II and 1
The largest lipid family in the mortar between your stratum corneum cells. Roughly half of that mortar, by mass, is ceramide. When it runs short, the wall leaks.
Why it is here
Half the mortar in your skin's wall. Applied alone they slow repair down, which is the kind of thing a ceramide brand would prefer you did not read. Ours come with the other two lipids.
Corneocytes sit in a lipid matrix organized into stacked lamellar sheets, and ceramides are the structural backbone of those sheets. Long-chain and acyl ceramides in particular span and rivet the layers together. Applying ceramides alone actually delays barrier recovery; they only help when delivered alongside cholesterol and free fatty acids, which is the finding that shaped how serious barrier creams are built.
The receipts
Substituting a ceramide-dominant physiologic lipid emollient for the previous moisturizer improved SCORAD in 22 of 24 patients by 3 weeks, with transepidermal water loss, stratum corneum integrity and hydration all improving over 20 to 21 weeks and lamellar membranes visible in stratum corneum that had largely lacked them at baseline.
Ceramide-dominant barrier repair lipids alleviate childhood atopic dermatitis: changes in barrier function provide a sensitive indicator of disease activity. Journal of the American Academy of Dermatology, 2002. cohort, n = 24 children with stubborn to recalcitrant atopic dermatitis. PMID 12140465
Applying one or two of the three stratum corneum lipids to perturbed skin delays barrier recovery; only equimolar mixtures of ceramides, cholesterol and free fatty acids allow normal recovery, and increasing the ratio of any one up to threefold accelerates it further.
Optimization of physiological lipid mixtures for barrier repair. Journal of Investigative Dermatology, 1996. in vivo animal, n = murine skin, with preliminary validation in damaged human skin. PMID 8618046
In practice
- Typical use
- 0.1 to 1 percent total ceramide in a barrier cream. The absolute number matters less than whether cholesterol and free fatty acids are in the bottle with it, and in what ratio.
- Pairs with
- Cholesterol, Free Fatty Acids, Ceramides + Cholesterol + Fatty Acids, Glycerin, Niacinamide
- Keep apart from
- Ceramides applied alone after barrier damage: this is the one real warning, and it comes from the lipid literature itself. Single-lipid application delayed recovery in the Man 1996 work. A ceramide-only product is not the same category of thing as a physiologic lipid mixture.
- Cautions
- None notable. Ceramides are structural rather than active, so nothing here stings or sensitizes in normal use. The main risk is buying a product that markets ceramides and delivers only ceramides.
Questions people ask
Are ceramides in skincare the same as the ones my skin makes?
Chemically very close, and the cosmetic ones are built to match the natural subclasses. Ceramide NP corresponds to ceramide 3, AP to 6-II and EOP to 1, the acylceramide that rivets the lamellar sheets together. Vernix caseosa work shows the pattern in newborn skin, and formulators have been copying that pattern deliberately.
Why do ceramides need cholesterol and fatty acids?
Because the barrier is a mixture, not an ingredient. In the 1996 work, applying one or two of the three lipids to damaged skin actually delayed recovery, and only complete mixtures allowed normal repair. Ceramides on their own are a half-built wall. This is the single most useful thing in the barrier literature and the least advertised.
Do ceramides help if my skin is not dry?
Less dramatically, and that is fine. The clinical evidence is strongest where the barrier is measurably compromised, as in atopic dermatitis or after damage. On intact skin a physiologic lipid cream is comfort and maintenance rather than repair. We would rather say that than sell you a rescue for a problem you do not have.