N-Acetyl-Glucosamine (NAG) is a simple amino sugar, a monosaccharide with an amino group as part of its structure. NAG is a nutrient, an intermediary metabolite, and a component of the glycocalyx coat carried by all the body’s cells. NAG is important for cell function. When it comes to intestinal function, it is a major constituent of the mucosal barrier layer that protects the living epithelium from digestive enzymes and other potentially damaging intestinal contents.* In addition to this, glucosamine has been shown to be of clinical importance in joint maintenance and renewal.*