Polyquaternium-37 (PQ-37) is a cationic acrylic homopolymer supplied as an inverse (water-in-oil) dispersion that activates upon dilution. In skin care, PQ-37 functions primarily as a rheology modifier and emulsion stabilizer that builds rich, cushiony textures at low use levels while improving slip and after-feel. Its positive charge enables substantive deposition on the negatively charged skin surface, forming an ultra-thin film that enhances softness without occlusion. Because the polymer arrives pre-neutralized and is cold-processable, it simplifies manufacturing, supports broad pH windows, and can stabilize challenging oil phases and actives — useful in lotions, creams, and hybrids where silky payoff and viscosity control are both required.

In hair care, PQ-37 is prized for antistatic and conditioning performance coupled with robust thickening. During shampoo or rinse-off use, dilution triggers polymer–surfactant complexation and deposition on hair fibers, improving wet combing, alignment, and frizz reduction while also aiding the co-deposition of lubricants (e.g., silicones, esters). In leave-on stylers and masks, its film-forming and antistatic behavior tames flyaways, boosts manageability, and enhances style retention without tack. Suppliers offer PQ-37 in different carriers (mineral oil or propylene glycol dicaprylate/dicaprate) to tune aesthetics and compatibility, enabling sprayable gels through to dense masks with low dosage and excellent stability.