Ceramides, explained in one page

Picture the outer layer of skin as a brick wall. The cells are the bricks; a mix of fats holds them together. Ceramides make up a large share of that mortar, alongside cholesterol and fatty acids.

Why they run low

Hot water, harsh cleansers, over-exfoliation, dry indoor air and age all wear the mortar down. Gaps let water escape and irritants in, which is why skin can feel tight, rough or stingy by the end of the day.

What ceramide skincare does

Moisturisers with ceramides top up those lipids. They work best alongside humectants such as glycerin or hyaluronic acid, which draw water in while the ceramides help keep it there.

How to get the most from them

• Apply to skin that is still slightly damp after cleansing.
• Use them morning and night, especially on days you use acids or retinoids.
• Pick fragrance-free formulas if your skin is sensitive.
• Be consistent — barrier repair takes a couple of weeks.