Glycerol (/ˈɡlɪsərɒl/; also called glycerine or glycerin) is a simple polyol compound. Known as one of the most versatile and valuable chemical substances, with over 1,500 known end uses. Glycerin is obtained from fats and oils during soap and fatty acid production and by transesterification. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic.

The glycerol backbone is found in those lipids known as glycerides. Due to having antimicrobial and antiviral properties it is widely used in FDA-approved wound and burn treatments. It is also widely used as a sweetener in the food industry and as a humectant in pharmaceutical formulations. Owing to the presence of three hydroxyl groups, glycerol is miscible with water and is hygroscopic in nature.