What it is
PEG-9 is a short-chain polyethylene glycol, a clear water-soluble liquid that attracts and holds water and dissolves a range of ingredients. In sunscreens it can help solubilize actives and other components and contribute to a smooth, hydrated feel. It is a common, versatile base ingredient across many skincare and cosmetic products.
Safety & warnings
PEGs of this size are widely used and generally well tolerated on intact skin. They are not considered notable fragrance allergens or comedogenic oils.
Origin & sourcing
Synthetic; produced by the controlled polymerization of ethylene oxide, with the number indicating the average degree of polymerization.
Questions everyone asks
What is PEG-9 used for?
It serves as a humectant and solvent, helping retain moisture and dissolve or blend other ingredients in a formula.
Does PEG-9 provide sun protection?
No. It is a formulation aid and has no ultraviolet-filtering function.