C22 Glucosylceramide (d18:1/22:0) is an endogenous glucosylceramide. Glucosylceramides are major constituents of skin lipid membranes where they play a role in maintaining the water permeability barrier. They are precursors in the synthesis of lactosylceramide , as well as oligoglycolipids and gangliosides. Phospholipase A2 (PLA2) type XIIA knockdown increases C22 glucosylceramide (d18:1/22:0) expression in rat brain. It is also increased in the brain, but not the liver or spinal cord, of mice fed a methionine-restricted diet. In human athletes, plasma levels of C22 glucosylceramide (d18:1/22:0) increase during exercise and return to basal levels during recovery. This product contains C22 glucosylceramide (d18:1/22:0) isolated from bovine buttermilk.