What it is
This ingredient is a glyceryl ester of isostearic acid that has been ethoxylated with about eight ethylene oxide units, combining an emollient fatty portion with a water-compatible PEG portion. That balance lets it act as a nonionic emulsifier while also softening and conditioning the skin. In sunscreens it helps build stable, comfortable emulsions with a smooth feel.
Safety & warnings
PEG glyceryl fatty-acid esters of this type are generally well tolerated and are not recognized fragrance allergens. Because isostearic acid is a branched fatty acid, the material is generally regarded as low in comedogenic potential relative to some straight-chain fatty esters, though overall formula context matters.
Origin & sourcing
Semi-synthetic; glycerin and isostearic acid esterified and then ethoxylated with polyethylene glycol.
Questions everyone asks
What role does this ingredient play?
It works as a nonionic emulsifier and emollient, helping stabilize emulsions while softening and conditioning the skin.
Is it oil-based or water-based?
It is amphiphilic, combining an emollient fatty (isostearate) portion with a water-loving PEG portion, which is what makes it an emulsifier.