Ceramides are a family of waxy lipid molecules that are composed of sphingosine and a fatty acid joined by an amide bond. They are found in high concentrations within the cell membrane of skin cells and make up 30% to 40% of the outer skin layer, or epidermis. Ceramides are important for retaining skin moisture and preventing the entry of germs into the body. They play a crucial role in forming a healthy skin barrier and help keep out harmful elements like pollution, toxins, and allergens. Ceramides are like the glue that holds skin cells together, helping to keep the skin barrier balanced and intact, sealing moisture in and keeping harmful irritants out.

Ceramides have been implicated in a variety of physiological functions including apoptosis, cell growth arrest, differentiation, cell senescence, cell migration, and adhesion. They have also been suggested to play a role in a number of pathological states including cancer, neurodegeneration, diabetes, microbial pathogenesis, obesity, and inflammation.

Ceramides may be found as ingredients in some topical skin medications used to complement treatment for skin conditions such as eczema. They are also used in cosmetic products such as some soaps, shampoos, skin creams, and sunscreens. Ceramides are a common ingredient in many over-the-counter serums, lotions, and creams, and they work well with emollients, which form a film to help keep skin hydrated.

There are 12 types of ceramides, but the three most common ones are ceramide 1, or ceramide EOS, ceramide 3, or ceramide NP, and ceramide 6-II, or ceramide AP. Ceramides are an essential component of the skins natural barrier, which makes them key for maintaining healthy-looking skin in all skin types. By helping to support a strong skin barrier, ceramides help seal in moisture and block out impurities, which is highly important for anyone looking to support healthy, hydrated skin.