What it is
This ingredient is a large branched-ester copolymer built from dimerized linoleic acid linked with octyldodecanol and propanediol units. In sunscreens and body oils it behaves as a heavy, non-volatile emollient that thickens oil phases, improves cushion, and helps suspend pigments or filters without a greasy snap. Its polymeric backbone gives a richer, more substantive skin feel than simple liquid esters.
Safety & warnings
As a high-molecular-weight ester it is generally well tolerated and not associated with notable sensitization. Because it is a rich, occlusive emollient based on fatty-acid chemistry, it may feel heavy and could contribute to congestion on very acne-prone skin, though polymeric esters of this type are typically less comedogenic than free fatty oils.
Origin & sourcing
Synthetic, produced by esterifying and polymerizing dimer linoleic acid (itself made from fatty acids) with octyldodecanol and propanediol.
Questions everyone asks
What does this ingredient do in a sunscreen?
It acts as a structuring emollient, adding cushion and body to the oil phase and helping keep UV filters and pigments evenly dispersed.
Is it derived from a natural oil?
It is synthetic but built in part from dimer linoleic acid, which is derived from plant-sourced fatty acids.