Ever heard of ceramides? Don’t worry if you haven’t, we've got you covered. Ceramides are a family of lipids (commonly called fats, although technically fats are a type of lipid1) that help to form the skin barrier.2 This barrier (the very top layer of the skin, also known as the stratum corneum), is made up of dead skin cells, squashed down flat and embedded in a matrix of lipids.2,3 It looks a bit like bricks and mortar, with the dead cells as the bricks and the lipid matrix as the mortar holding it all together. In healthy skin, ceramides make up approximately 40-50% of this lipid matrix. Other components are cholesterol (around 25%) and free fatty acids (10­-15%).4

Ceramides have a lot of interesting attributes, like being one of the most hydrophobic lipids found in membranes2 (that means they really dislike water). But they're made up of two parts – one half that really dislikes water, and one half that really likes it (figure 1). Because of this dual-structure, the parts that dislike water all face each other and the parts that love water sit in neat rows on the outside, helping form the protective barrier layer of our skin and trapping moisture inside (figure 2).1

Have they had any success? Read the next article to find out.