Our outer layer of the skin, the stratum corneum, has a multilamellar structure (essentially a fine membrane), made up of lipids (fats), to form a non-permeable barrier. This keeps water inside the skin, and acts as the first defense against external aggressors. The lipids which make up the majority of this are known as ceramides, which are produced naturally in the body from a range of other naturally-occurring lipids, which we class here as essential lipids (not the same as essential fatty acids, which are deemed ‘essential’ as the body cannot produce these naturally.) Using these lipids in skincare helps to support the natural skin barrier, preventing water-loss to keep skin hydrated and balanced.