What it is
Hydrolyzed Wheat Protein/PVP Crosspolymer is a reaction product in which fragments of enzymatically or acid-hydrolyzed wheat protein are linked to polyvinylpyrrolidone. The combination yields a substantive, flexible film on the skin surface that helps even the deposit of other ingredients and impart a smooth feel. In sunscreens it is a minor functional additive rather than a UV filter, contributing to the cosmetic finish and adhesion of the formula.
Safety & warnings
Hydrolyzed wheat protein ingredients can be a concern for people with wheat allergy, and rare cases of contact urticaria or sensitization have been reported with high-molecular-weight wheat protein derivatives; those with diagnosed wheat allergy may wish to use caution. Most consumers tolerate it well in leave-on cosmetics.
Origin & sourcing
Semi-synthetic: the protein portion is derived from wheat (Triticum), while the PVP portion is a synthetic polymer; the two are combined into a crosspolymer.
Questions everyone asks
Is this a UV filter?
No. It is a film-forming and conditioning additive, not a UV filter; the sunscreen's protection comes from its active UV filters.
Does it contain gluten?
It is derived from wheat protein, so people with wheat allergy or strict gluten avoidance for skin contact may wish to be cautious, though it is used at low levels.