A ceramide is a lipid molecule which plays an essential role in both water-retention function and barrier function in the stratum corneum – the outer layer of skin.
Professor Derek explains how ceramides work in this 1 minute interview.
"All You Need To Know About Lipids". Professor Derek Richard. Translational Research Institute Australia. QLD. August 2020. Transcript.
"Lipids and ceramides are both fat molecules, you know, a ceramide is a lipid, it's just one of the types of lipids that we have within our cells. Each one of our cells has a liquid internal, so a fluid contains internal but holding that internal together is a lipid layer around the cell and so that holds everything in place. It is the cell's defence, it's relatively impervious to other chemicals moving in, except for the ones that it wants to move in and things that it wants to move out.
We think of fats being bad things, they're not bad things we need fats. All our vitamins, almost all vitamins are dissolved in fats and we need to have fat there as well. ( . . . ) All life on this planet uses lipids as a way of encapsulating, even the bacteria. Bacteria have a wall around the rigid wall around them as well but we have a lipid layer underneath that wall as well.
(Lipids are) an essential component in life and ceramides are a critical component of the human cell membrane."