What it is
Steareth-20 is an ethoxylated fatty alcohol, formed by reacting stearyl alcohol with about twenty units of ethylene oxide to create a water-dispersible emulsifier. It helps blend oil and water phases into stable emulsions and can solubilize oils into aqueous systems. In sunscreens it is commonly used to keep the formula uniform and to improve spreadability.
Safety & warnings
Steareth-20 is generally well tolerated in cosmetic use. As an ethoxylated ingredient it is produced through processing that requires purification, and it is used safely as a standard emulsifier across many product types.
Origin & sourcing
Synthetic; produced by ethoxylating stearyl alcohol, which may be plant- or petroleum-derived.
Questions everyone asks
What does Steareth-20 do in a formula?
It is a nonionic emulsifier that blends oil and water into a stable, uniform product and helps it spread evenly.
Is Steareth-20 a UV filter?
No. It is an emulsifier and does not provide UV protection.