Butylene glycol is an organic alcohol derived from petroleum and is water-soluble.

Butylene glycol is a commonly used ingredient that plays multiple roles in cosmetics, including as a humectant, texture enhancer, solvent, and penetration booster. Research indicates butylene glycol not only helps raise water content in the skin (aka hydration) but may also contribute to decreasing roughness on the surface of the skin (depending on how it’s combined in the formula). While not known as a preservative in and of itself, some of butylene glycol’s properties can help boost a formula’s stability against microorganisms that may harm the skin’s surface.