What it is
Stearoyl glutamic acid is an acylated amino acid made by joining stearic acid to the amino acid glutamic acid, giving it a fatty tail and an amino-acid head. It functions as a mild anionic surfactant and emulsifier and is frequently used to coat and disperse mineral UV filter particles such as titanium dioxide and zinc oxide so they spread evenly and resist clumping. This dispersing role makes it common in mineral and hybrid sunscreens.
Safety & warnings
Amino-acid-based surfactants of this type are generally regarded as mild and well tolerated, with a low irritation potential. As a coating and dispersing agent it is typically used at low levels in the formula.
Origin & sourcing
Synthetic, produced by acylating glutamic acid, an amino acid, with stearic acid that can be of plant or animal origin.
Questions everyone asks
What does stearoyl glutamic acid do in sunscreen?
It works as a mild emulsifier and as a coating that disperses mineral UV filter particles so they spread evenly without clumping.
Is stearoyl glutamic acid harsh on skin?
It is an amino-acid-derived surfactant generally regarded as mild and well tolerated at cosmetic use levels.