Why is sorbitol used in toothpaste?

Sorbitol is a common ingredient that can be found in various toothpaste brands.  It is a type of sugar alcohol that may be derived from various fruits like apples, peaches, and pears.  Depending on the toothpaste formulation, sorbitol may be added as one of the ingredients because of its sweetening effect.  Beyond the generic menthol or minty tastes, many types of toothpaste also taste sweet, and using sorbitol is a great way to give this type of taste.

Sorbitol is also used in toothpaste as a humectant and thickener.  Humectants like sorbitol function to prevent the toothpaste from hardening when the tube is opened or when the paste is exposed to air.  Toothpastes that are made without sorbitol may easily dry and become hard and flaky.  Sorbitol is also a thickening agent which makes the paste more stable and compact but still soft and moist.  Without sorbitol, toothpastes may either become too thick and hard or even have a more watery consistency.

Some brands of toothpaste are also manufactured to become gel-like and have a more transparent color. To achieve this effect, toothpastes take advantage of sorbitol’s high refractive index.  With sorbitol, toothpastes can be formed into gels that are transparent.  Adding color to the transparent gel is also sometimes a cause for concern yet sorbitol has a reflective index that is high enough and good enough for this particular purpose.

Since sorbitol is naturally derived from fruits, health experts usually consider it as a healthy ingredient for products such as mouthwashes and toothpastes.  The only significant concern with sorbitol is that it can promote Irritable Bowel Syndrome or lead to problems in the gastrointestinal system if consumed in large amounts.  This is mainly because sorbitol also functions as a laxative.  This concern, though, only applies to cases wherein sorbitol is added to food items as a sweetener.