What Is Mannitol?

FDA regulations at 21 CFR 180.25 define mannitol as a hexahydric alcohol that differs from sorbitol principally by having a different optical rotation. They list it as an interim food additive used at levels not to exceed 98 percent in pressed mints, 31 percent in chewing gum, 40 percent in soft candy, 8 percent in confections and frostings, and less than 2.5 percent in most other foods, and say continued uses are contingent on timely and adequate progress reports of required tests and no indication of increased risk to public health during the test period.

The regulation requires foods whose reasonably foreseeable consumption may result in a daily intake of 20 grams of mannitol to carry the statement "Excess consumption may have a laxative effect." A 2016 review in the International Journal of Dentistry says eating sorbitol and mannitol generates far more severe gastrointestinal disturbances than xylitol.

Mannitol is also a prescription drug. A mannitol injection label on DailyMed lists its uses as the reduction of intracranial pressure and treatment of cerebral edema, and the reduction of elevated intraocular pressure.