Levoglucose (L-glucose) is the stereoisomer of D-glucose. L-Glucose does not occur naturally in higher living organisms, but can be synthesized in the laboratory. L-Glucose is indistinguishable in taste from D-glucose, but cannot be used by living organisms as source of energy because it cannot be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway. Levoglucose may be used as diagnostic aid. It has been investigated as a non-nutritive food sweetener. However, L-glucose produced significant laxation, with an average of 4 to 5 loose watery stools in a 24-hour period. This laxative property clearly reduced the use of L-glucose as a food additive. The mechanism of laxation after L-glucose ingestion is unknown, but malabsorption of the compound with secondary osmotic diarrhea is likely. L-glucose is a well-tolerated, safe, and efficacious means of cleansing the colon for colonoscopy. The L-glucose pentaacetate anomers could be used as novel insulinotropic tools in the treatment of non-insulin-dependent diabetes mellitus.