Mannitol is a beneficial derived sugar which works on a micro-cellular level – transporting valuable nutrients and other chemicals directly into each cell especially the brain. The arteries of the blood–brain barrier are much more selective than normal arteries. Mannitol is able to open the barrier by temporarily shrinking the endothelial cells and stretching the tight connections between them.

Mannitol does not lead to elevated levels of blood sugar, as glucose may, and is used extensively in the food industry as a sweetener for patients with diabetes.