What it is
Triisostearin is a branched triglyceride formed from glycerin and isostearic acid, giving it a soft, non-greasy emollient character and good oxidative stability. It conditions the skin surface, helps bind powders and pigments, and can thicken anhydrous or oil-rich systems. It appears frequently in sun sticks, balms, and tone-up sunscreens where it contributes to a smooth, even application.
Safety & warnings
Generally well tolerated and considered low risk for irritation. As a branched ester it is typically regarded as having low comedogenic potential compared with straight-chain fatty esters, though very rich, occlusive formulas may not suit acne-prone users.
Origin & sourcing
Synthetic ester made from glycerin and isostearic acid, a branched fatty acid; raw materials may be plant- or petroleum-derived.
Questions everyone asks
What does triisostearin do in a sunscreen?
It acts as an emollient that smooths application, conditions skin, and helps bind and disperse pigments and powders in stick or balm formats.
Is triisostearin greasy?
It is an oily ester but its branched structure gives a relatively light, non-tacky feel, so it is often chosen for a smooth rather than heavy finish.