Ceramides

In Great Britain and Northern Ireland alike, ingredients present at 1% or more are listed in descending order of weight, and ingredients below 1% may be listed in any order after them. Ceramides are exactly the kind of ingredient likely to sit under that line, so an ingredient list can confirm that a declared ceramide is present while disclosing neither its percentage, nor its rank among the other sub-1% ingredients, nor a lipid ratio.^{[10, 11]In Great Britain and Northern Ireland alike, ingredients present at 1% or more are listed in DESCENDING order of weight; ingredients below 1% may be listed in ANY order after them. An ingredient list can therefore confirm that a declared ceramide is present, but usually cannot reveal its percentage, its rank within the sub-1% group, or a lipid ratio — and ceramides are exactly the kind of ingredient likely to sit below that 1% line.Directly tested by the source[10] Office for Product Safety and Standards. Regulation 1223/2009 and the Cosmetic Products Enforcement Regulations 2013: Great Britain. Updated 29 June 2026.Tier 1[11] Office for Product Safety and Standards. Regulation 1223/2009 and the Cosmetic Products Enforcement Regulations 2013: Northern Ireland. Updated 29 June 2026.Tier 1}

A ratio printed on a carton is therefore a manufacturer’s claim, and one the brand must be able to substantiate on request. It is not a specification that can be checked at the point of sale.

In 58 adults with dry, eczema-prone skin, a specific ceramide-containing cream improved selected 28-day measures against a comparator. The trial was funded by the company that owns the brand tested, which does not invalidate it and does mean it is not independent.^{[8]In 58 adults with dry, eczema-prone skin, a specific ceramide-containing cream improved selected 28-day measures against a comparator — in a trial funded by the brand's owner.Directly tested by the source[8] Andrew PV, Williams SF, Brown K, et al. Topical supplementation with physiological lipids rebalances skin barrier function. 2025.Tier 2}

This is the clearest positive result in the category, and its ceiling is legible in the same sentence: selected measures, 28 days, one named formulation, one recruited population.

In a three-week trial of 39 childrenrandomised 1:1:1 — thirteen per arm— no statistically significant efficacy difference was detected at any time point between an over-the-counter petrolatum ointment, the ceramide-dominant 3:1:1 prescription cream and a glycyrrhetinic-acid cream. The petrolatum was at least 47 times more cost-effective.^{[5, 6]In a three-week trial of 39 children — thirteen per arm — no statistically significant efficacy difference was detected between a petrolatum ointment, a ceramide-dominant 3:1:1 prescription cream and a glycyrrhetinic-acid cream at any time point, and the petrolatum was at least 47 times more cost-effective. The trial was not designed to establish equivalence, and its authors say the sample was not sufficient to establish superiority either. In Cochrane's reanalysis, itch change for the ceramide product versus petrolatum was MD 4.51 mm (95% CI −16.54 to 25.56, p=0.67) — an estimate so imprecise it is compatible with a meaningful advantage either way, which numerically favoured petrolatum.Directly tested by the source[5] van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen APM, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database of Systematic Reviews. 2017;(2):CD012119.Tier 1[6] Miller DW, Koch SB, Yentzer BA, et al. An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis. Journal of Drugs in Dermatology. 2011;10(5):531–537.Tier 2}

What that yields in practice is a comparator rather than a verdict. A simple, well-formulated emollient belongs in the conversation on its merits, and price is a legitimate part of the decision rather than a compromise on the result.

A ceramide-containing cream is also an occlusive, a humectant and a vehicle. A result from the finished formula cannot be assigned to the ceramides in it, because those other properties vary with the formulation.^{[5, 6, 7, 8]iA result from a complete ceramide-containing formulation cannot be assigned to ceramides alone, because vehicle, occlusion, humectants and delivery all vary with it.Inferred from adjacent evidence[5] van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen APM, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database of Systematic Reviews. 2017;(2):CD012119.Tier 1[6] Miller DW, Koch SB, Yentzer BA, et al. An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis. Journal of Drugs in Dermatology. 2011;10(5):531–537.Tier 2[7] Koppes SA, Charles F, Lammers LA, Frings-Dresen MH, Kezic S, Rustemeyer T. Efficacy of a cream containing ceramides and magnesium in the treatment of mild to moderate atopic dermatitis. Acta Dermato-Venereologica. 2016;96(7):948–953.Tier 2[8] Andrew PV, Williams SF, Brown K, et al. Topical supplementation with physiological lipids rebalances skin barrier function. 2025.Tier 2}

A change in transepidermal water loss carries the same limit. It records a change in water loss; it does not identify a ceramide deficiency, and it does not establish that ceramides caused the change.^{[3, 7, 8]iA change in TEWL does not identify a ceramide deficiency, nor by itself prove that topical ceramides caused the change.Inferred from adjacent evidence[3] Janssens M, van Smeden J, Gooris GS, et al. Increase in short-chain ceramides correlates with an altered lipid organization and decreased barrier function in atopic eczema patients. Journal of Lipid Research. 2012;53(12):2755–2766.Tier 3[7] Koppes SA, Charles F, Lammers LA, Frings-Dresen MH, Kezic S, Rustemeyer T. Efficacy of a cream containing ceramides and magnesium in the treatment of mild to moderate atopic dermatitis. Acta Dermato-Venereologica. 2016;96(7):948–953.Tier 2[8] Andrew PV, Williams SF, Brown K, et al. Topical supplementation with physiological lipids rebalances skin barrier function. 2025.Tier 2}

The consequence is not that the category is ineffective. It is that the evidence supports particular formulations rather than the ingredient class, which is where a recommendation has to be made.

No human clinical validation has been located establishing a ceramide-dominant 3:1:1 molar ratio as a requirement for a finished product to work.^{[no source found]No human clinical validation was located establishing one ceramide-dominant 3:1:1 molar ratio as a universal requirement for a finished product to work.We looked and found no source either way} Nor has a validated consumer-facing ceramide percentage or threshold been located that predicts clinical efficacy across finished products.^{[no source found]No validated consumer-facing ceramide percentage or threshold was located that predicts clinical efficacy across finished products.We looked and found no source either way}

Neither figure could be read off a carton in any case. Selection therefore rests on what is observable: the evidence attached to the named product, its cost, and whether it is tolerated well enough to stay in use.

A well-formulated simple emollient is a legitimate recommendation rather than an inferior one. In the head-to-head trial described above, no difference was detected between an over-the-counter petrolatum ointment and the ceramide-dominant prescription product, at a fraction of the price. For a client on a budget that is a real option rather than a downgrade, and saying so costs the category nothing it can evidence.

The literature reviewed here reports efficacy and barrier measures without adverse-effect data, so none of it characterises the tolerability profile of ceramide-containing products, and the instructions supplied with the particular product are what govern its use.

The attribution problem runs in this direction too. What is applied is a formulation — vehicle, occlusive, humectant and preservative system together — so a reaction identifies the product rather than the lipid class, and a client who reacted to one ceramide cream has not thereby been shown to react to ceramides.^{[5, 6, 7, 8]iA result from a complete ceramide-containing formulation cannot be assigned to ceramides alone, because vehicle, occlusion, humectants and delivery all vary with it.Inferred from adjacent evidence[5] van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen APM, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database of Systematic Reviews. 2017;(2):CD012119.Tier 1[6] Miller DW, Koch SB, Yentzer BA, et al. An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis. Journal of Drugs in Dermatology. 2011;10(5):531–537.Tier 2[7] Koppes SA, Charles F, Lammers LA, Frings-Dresen MH, Kezic S, Rustemeyer T. Efficacy of a cream containing ceramides and magnesium in the treatment of mild to moderate atopic dermatitis. Acta Dermato-Venereologica. 2016;96(7):948–953.Tier 2[8] Andrew PV, Williams SF, Brown K, et al. Topical supplementation with physiological lipids rebalances skin barrier function. 2025.Tier 2}

No source reviewed here sets a threshold at which a ceramide-containing product is reduced or stopped; that decision follows the presentation and the instructions for the product in use. The point at which it stops being a cosmetic question at all is set out under referral below.

The native matrix is often described as roughly 50% ceramides, 25% cholesterol and 10–15% free fatty acids by mass. A composition by mass is a different quantity from the molar ratio used in formulation, and the two are quoted interchangeably.^{[1]The native matrix is often described as roughly 50% ceramides, 25% cholesterol and 10–15% free fatty acids by mass — which is a different quantity from the molar ratios used in formulation.Directly tested by the source[1] van Smeden J, Janssens M, Gooris GS, Bouwstra JA. The important role of stratum corneum lipids for the cutaneous barrier function. Biochimica et Biophysica Acta. 2014;1841(3):295–313.Tier 4}

Supported statement:the native matrix is ceramide-dominant by mass, in approximate figures, and that is a different number from a formulation’s molar ratio.

The figure traces to a single optimisation experiment in an acute barrier-disruption model in hairless mice. It began from equimolar mixtures of ceramides, cholesterol and fatty acids, which allowed normal recovery, and repair accelerated as the ratio of anyof the three was increased up to three-fold — cholesterol-dominant and fatty-acid-dominant mixtures worked as well as the ceramide-dominant one. Its only human note is that similar preliminary results were obtained in damaged human skin. Three of the paper’s four authors — Elias, Feingold and Thornfeldt — are named inventors on the EpiCeram patent, the ceramide-dominant product marketed on that ratio.^{[4]The foundational optimisation experiment behind the 3:1:1 ratio was an acute barrier-disruption model in hairless MICE, not a human clinical validation. It did not establish a uniquely ceramide-dominant three-component requirement: it started from equimolar mixtures, and recovery accelerated as the ratio of ANY of the tested lipids was increased up to three-fold. Its only human note is that 'similar preliminary results were obtained in damaged human skin'.Directly tested by the source[4] Man MQ, Feingold KR, Thornfeldt CR, Elias PM. Optimization of physiological lipid mixtures for barrier repair. Journal of Investigative Dermatology. 1996;106(5):1096–1101.Tier 3}

Supported statement: the three-component ceramide-dominant ratio is later product shorthand for a mouse experiment in which no single lipid held the dominant position.

The trial behind that sentence was not designed as an equivalence or non-inferiority study, and its authors state that 39 subjects were not sufficient to establish the petrolatum as superior either. Cochrane’s reanalysis of the itch outcome shows how imprecise the comparison is: MD 4.51 mm (95% CI −16.54 to 25.56, p=0.67), an interval wide enough to contain a meaningful advantage in either direction, which happens to favour petrolatum numerically.^{[5, 6]In a three-week trial of 39 children — thirteen per arm — no statistically significant efficacy difference was detected between a petrolatum ointment, a ceramide-dominant 3:1:1 prescription cream and a glycyrrhetinic-acid cream at any time point, and the petrolatum was at least 47 times more cost-effective. The trial was not designed to establish equivalence, and its authors say the sample was not sufficient to establish superiority either. In Cochrane's reanalysis, itch change for the ceramide product versus petrolatum was MD 4.51 mm (95% CI −16.54 to 25.56, p=0.67) — an estimate so imprecise it is compatible with a meaningful advantage either way, which numerically favoured petrolatum.Directly tested by the source[5] van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen APM, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database of Systematic Reviews. 2017;(2):CD012119.Tier 1[6] Miller DW, Koch SB, Yentzer BA, et al. An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis. Journal of Drugs in Dermatology. 2011;10(5):531–537.Tier 2}

Supported statement: a small three-week trial detected no difference between the two, at a fraction of the cost.

The headline figure is a 4.1 to 5.5-fold rise in ceramide synthesis after six days in cultured human keratinocytes, in work authored at a cosmetics manufacturer. The same paper also reports a topical human arm in dry skin, in which stratum-corneum ceramides and free fatty acids increased and transepidermal water loss fell; the accessible abstract gives no denominator, body site, formulation or effect size for it.^{[9]The often-cited niacinamide-to-ceramide mechanism derives from cultured normal human keratinocytes — a 4.1 to 5.5-fold rise in ceramide synthesis after six days — in work authored at a cosmetics manufacturer. The same paper also reports a topical human arm in dry skin, with increased stratum-corneum ceramides and free fatty acids and reduced TEWL; the accessible abstract gives no denominator, site, formulation or effect size for it.Directly tested by the source[9] Tanno O, Ota Y, Kitamura N, Katsube T, Inoue S. Nicotinamide increases biosynthesis of ceramides as well as other stratum corneum lipids. British Journal of Dermatology. 2000;143(3):524–531.Tier 3}

Supported statement:the mechanism has in-vitro support and an incompletely reported human signal, and the size of any effect on a client’s stratum corneum is unquantified.

For a specific formulation with a trial behind it, the evidence supports the recommendation. For the ingredient in the abstract, the question cannot be answered. In the only head-to-head comparison, an over-the-counter petrolatum ointment was at least 47 times more cost-effective and no difference in effect was detected, which makes price a legitimate part of the decision.^{[5, 6]In a three-week trial of 39 children — thirteen per arm — no statistically significant efficacy difference was detected between a petrolatum ointment, a ceramide-dominant 3:1:1 prescription cream and a glycyrrhetinic-acid cream at any time point, and the petrolatum was at least 47 times more cost-effective. The trial was not designed to establish equivalence, and its authors say the sample was not sufficient to establish superiority either. In Cochrane's reanalysis, itch change for the ceramide product versus petrolatum was MD 4.51 mm (95% CI −16.54 to 25.56, p=0.67) — an estimate so imprecise it is compatible with a meaningful advantage either way, which numerically favoured petrolatum.Directly tested by the source[5] van Zuuren EJ, Fedorowicz Z, Christensen R, Lavrijsen APM, Arents BWM. Emollients and moisturisers for eczema. Cochrane Database of Systematic Reviews. 2017;(2):CD012119.Tier 1[6] Miller DW, Koch SB, Yentzer BA, et al. An over-the-counter moisturizer is as clinically effective as, and more cost-effective than, prescription barrier creams in the treatment of children with mild-to-moderate atopic dermatitis. Journal of Drugs in Dermatology. 2011;10(5):531–537.Tier 2}

No validated threshold exists. No consumer-facing ceramide percentage has been located that predicts clinical efficacy across finished products, and the concentration usually cannot be read from an ingredient list in any case.^{[no source found]No validated consumer-facing ceramide percentage or threshold was located that predicts clinical efficacy across finished products.We looked and found no source either way}

Cosmetic ingredients rarely attract independent funding. The positive adult trial reviewed here was funded by the brand’s owner, and the authors of the foundational ratio paper are named inventors on the patent for the product built to it. The interest is disclosed on every source in the list below rather than on a selection of them.^{[8]In 58 adults with dry, eczema-prone skin, a specific ceramide-containing cream improved selected 28-day measures against a comparator — in a trial funded by the brand's owner.Directly tested by the source[8] Andrew PV, Williams SF, Brown K, et al. Topical supplementation with physiological lipids rebalances skin barrier function. 2025.Tier 2}