What it is
This is a crosslinked copolyester built from trimethylpentanediol, adipic acid, and glycerin. In sunscreens it forms a flexible film that helps distribute UV filters evenly and supports more uniform, longer-lasting coverage with a smooth, comfortable feel. It can also adjust viscosity and enhance the cosmetic finish of the product.
Safety & warnings
As a large film-forming polymer, it is generally well tolerated in leave-on products. It is not a recognized fragrance allergen and is not typically associated with comedogenicity.
Origin & sourcing
Synthetic, produced by polymerizing trimethylpentanediol, adipic acid, and glycerin into a crosslinked polyester.
Questions everyone asks
Why is this crosspolymer added to sunscreens?
It forms a flexible film that helps spread and hold UV filters in place, supporting more even coverage and a smoother finish.
Is it a moisturizing ingredient?
Its main role is film forming and texture, though the film can help reduce the sensation of dryness; it is not primarily a humectant.