What it is
PEG-8 is a low-molecular-weight polyethylene glycol that is liquid and freely water-soluble. In formulations it functions as a humectant, a solvent for other ingredients, and a skin-conditioning agent, and it can help carry actives within the water phase. It is widely used across skincare and sun-care products as a versatile, well-characterized base ingredient.
Safety & warnings
PEG-8 is widely used and generally considered well tolerated in cosmetics. As a water-soluble polymer it is not comedogenic and is not a fragrance allergen. Quality-grade PEGs are purified to limit residual reaction byproducts, and the ingredient is used safely across many leave-on and rinse-off products.
Origin & sourcing
Synthetic. It is manufactured by the controlled polymerization of ethylene oxide, yielding a polymer with an average of about eight repeating units.
Questions everyone asks
What does PEG-8 do in a formula?
It works mainly as a humectant and solvent, helping retain moisture and dissolve other ingredients in the water phase.
Is PEG-8 a UV filter?
No. It is a functional base ingredient and does not provide any sun protection.