Ceramides and eczema — why your moisturiser ingredient list matters

The skincare market is full of ingredients claiming to help eczema. Most of them don't have meaningful evidence. Ceramides do — and understanding what they are and how they work helps you cut through the marketing and choose products that will actually make a difference.

What ceramides are

Ceramides are lipid molecules — a type of fat — that are a structural component of the skin barrier. They make up approximately 50% of the lipid matrix in the stratum corneum, the outermost layer of the skin. Along with cholesterol and fatty acids, they form the "mortar" that holds the skin barrier's "brick" structure together.

There are multiple types of ceramide in human skin, classified by their chemical structure. The most important for barrier function are ceramide NP (previously called ceramide 3), ceramide AP (ceramide 6-II), and ceramide EOP (ceramide 1). These specific types appear on cosmetic ingredient lists and are the ones with clinical evidence for barrier repair.

What happens in eczema

In eczema-prone skin, ceramide levels are measurably reduced compared to unaffected skin — sometimes by as much as 50%. This isn't just a consequence of the condition; ceramide deficiency is part of the mechanism. Without sufficient ceramides, the spaces between skin cells aren't properly sealed. Water escapes from the skin — a process called transepidermal water loss — and allergens, irritants, and microorganisms can enter.

The inflammation that characterises eczema further reduces ceramide production, creating a self-reinforcing cycle: inflammation depletes ceramides, which worsens barrier function, which allows more irritants in, which drives more inflammation.

The evidence for topical ceramides

Multiple clinical studies have shown that ceramide-containing moisturisers improve barrier function in eczema patients. A 2013 study in Pediatric Dermatology found that a ceramide-dominant emollient significantly reduced transepidermal water loss and improved eczema severity scores compared to a standard emollient. A 2018 meta-analysis confirmed that ceramide-containing moisturisers produce greater improvements in eczema outcomes than comparator moisturisers.

The evidence is strong enough that ceramide-containing emollients are now specifically recommended in eczema treatment guidelines in several countries, including by the National Eczema Association in the US.

How to read an ingredient list

Look for ceramide NP, ceramide AP, ceramide EOP, ceramide NS, or ceramide AS. "Ceramide" on its own without a specifier may indicate a synthetic analogue of varying quality. Phytosphingosine and sphingosine are ceramide precursors — the skin can convert them to ceramides — and are a reasonable alternative.

Ceramides work best in combination with the other components of the natural skin barrier: cholesterol and fatty acids. Products that contain all three, in approximately the ratio found in healthy skin (ceramides 3:1:1 with cholesterol and fatty acids), show better barrier repair results than ceramide-only formulations. CeraVe, a widely available and relatively affordable brand, uses this formulation principle.

What ceramides won't do

Ceramides repair and support the skin barrier. They don't suppress the immune-mediated inflammation that drives eczema flares in the way that topical steroids do. During an active flare, ceramide moisturisers are an important component of management but not sufficient alone for significant acute inflammation. The protocol uses them as part of the barrier repair stack rather than as a standalone treatment.