Galactose is found in sugar beets and dairy products. It is a sugar and is also known as brain sugar. Because it has food energy it is known as a nutritive sweetener. It is not very water-soluble and is less sweet than glucose. When joined with glucose it forms the disaccharide known as lactose found in milk. Alone glactose is known as a monosaccharide.

Glactose is found in a number of natural products combined with other sugars, the most notable being lactose (combination of glactose and glucose). It is the glactose in lactose that causes an inability to digest dairy products known as lactose intolerance. It is also found in polysaccharides, carbohydrates and lipids. Lipids are found in the nerve tissue and the brain. Glactose is used in medicines and synthetic substances.