Skim through

What it does: binding, emulsion stabilizing, film forming, viscosity controlling

Also called: cyamopsis tetragonoloba gum

The science

A plant-derived (coming from the seeds of Cyamopsis tetragonoloba, aka guar) big, branched sugar molecule that is hydrating and used as a gelling agent. With emulsifying properties, guar gum combines equally well with both solids and liquids, helping to contribute thickness and fluffiness to a formula. Its surfactant quality helps to enhance lather, and its exceptional conditioning ability helps to soften both skin and hair. Guar gum is also reputed to extend the shelf life of various skincare products.

Benefits for your hair

Promotes smoothness

Guar gum hydrates the hair by sealing in moisture. It acts as a conditioner and makes hair smooth and shiny.

Prevents breakage and frizz

Guar gum, as a conditioner, reduces breakage, frizzi and static in hair.

TLDR 

Guar gum is a great emulsifier which hydrates and conditions hair, improving the smoothness and reducing breakage and frizz.