Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group.

Each of these rings is subject to further isomerism, depending on the relative orientation of the anomeric hydroxy group.

It was first isolated from wood by Finnish scientist, Koch, in 1881,[3] but first became commercially viable, with a price close to sucrose, in 1930.

In animal medicine, xylose is used to test for malabsorption by administration in water to the patient after fasting.

[12] High xylose intake on the order of approximately 100 g/kg of animal body weight is relatively well tolerated in pigs, and in a similar manner to results from human studies, a portion of the xylose intake is passed out in urine undigested.