Inulin is a polysaccharide (one of the fructans) that consists almost exclusively of linked fructose subunits. Inulins; compounds mainly produced in chicory, onion, Jerusalem artichoke, and garlic; count among fructans.
Inulin is an indigestible fiber that promotes the growth of beneficial bacteria on the skin surface. Thus, they have positive health effects and are even implicated in disease prevention (prebiotic effects).
Like other polysaccharides, Inulin is an excellent humectant that improves dermal moisture content, enhancing the skin's water-binding ability.
Today, inulins and other polyfructoses (fructans), usually extracted from chicory, are used in yogurts and other dairy foods to enhance their nutritional value (functional foods); therefore, it is a safe and well-studied ingredient for skincare formulations.