What it is
Ammonium Polyacryloyldimethyl Taurate is a crosslinked polymer built from acrylamido-2-methylpropane sulfonic acid units neutralized as the ammonium salt. In formulas it swells in water to build viscosity, suspend pigments and other insoluble ingredients, and stabilize oil-in-water systems, giving sunscreens a smooth, non-greasy slip. It tolerates electrolytes and a fairly wide pH range, which makes it convenient for cream-gel and lotion textures.
Safety & warnings
Large polymeric molecules of this type are not meaningfully absorbed and are generally well tolerated, with a low reported rate of irritation or sensitization. It is not a recognized fragrance allergen and is non-comedogenic. As with any gelling agent, the finished product's overall formulation drives tolerability more than this single component.
Origin & sourcing
Synthetic polymer manufactured by free-radical polymerization of acrylamido-methylpropanesulfonic acid monomers, then neutralized with ammonia.
Questions everyone asks
What does ammonium polyacryloyldimethyl taurate do in sunscreen?
It thickens the water phase and stabilizes the emulsion, helping suspend filters and pigments while giving the product an even, lightweight feel on the skin.
Is it natural or synthetic?
It is a fully synthetic polymer made by polymerizing sulfonic acid monomers and neutralizing them with ammonia.