Allulose is a low-calorie monosaccharide classified as a rare sugar. Chemically, it is the C-3 epimer of D-fructose. Unlike conventional sugars, allulose is absorbed by the small intestine but not metabolized by the body, resulting in negligible caloric contribution. It has received GRAS status from the FDA and is excluded from total and added sugar counts on US nutrition labels. Allulose exhibits excellent functional properties — it browns like sugar via Maillard reaction, lowers freezing point in frozen desserts, and provides bulk similar to sucrose. It does not promote tooth decay and has been shown to have beneficial effects on blood glucose and lipid metabolism.