Sodium Polymethacrylate

What is Sodium Polymethacrylate?

Sodium Polymethacrylate is a water-soluble sodium salt derived from cross-linked polymethacrylic acid, a synthetic anionic polymer produced from acrylic monomers via polymerization and neutralization. Commonly incorporated into lotions, creams, gels, shampoos, and makeup, it excels in aqueous-based formulations. Upon water contact, it swells into a three-dimensional gel matrix, dramatically boosting viscosity to suspend particles and prevent settling. This structuring action fortifies emulsions against phase separation, enhances shear-thinning for easy spreading, and deposits sheer films that boost water repellency and adhesion on skin or hair. Additionally, it scatters light to impart opacity, transforming clear solutions into luxurious, pearlescent textures ideal for everyday personal care items.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Binder
Helps hold solid ingredients together to form cohesive tablets, compacts, or sticks, improving pressability, integrity, and wear of the finished product.
Emulsion stabilizer
Improves emulsion robustness by preventing droplet coalescence and phase separation, often by thickening, structuring, or strengthening the interfacial layer.
Film former
Creates a continuous film on skin or hair to improve wear, water resistance, transfer resistance, shine, or hold in sunscreens, makeup, and styling products.
Viscosity controlling agent
Adjusts thickness to the desired level for stability and usability, improving dispensing, suspension, and texture across many formulation types.
Binding
Provides cohesion by helping ingredients stick together, improving the strength and integrity of pressed powders, tablets, or solid bars.
Opacifying agent
Makes a formula less transparent to create a creamy, opaque look; can also help visually mask suspended particles and improve aesthetic uniformity.

Benefits

Provides smooth, spreadable textures for comfortable application

Strengthens product stability to maintain consistency over time

Creates protective films enhancing wear and resistance to water in makeup

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Users of emulsified creams and lotions seeking non-separating formulas
Those with rare allergies to acrylate polymers
Individuals applying long-wear or water-resistant cosmetics
Individuals sensitive to synthetic thickeners
People preferring opaque, visually appealing skincare products
Users avoiding petroleum-derived ingredients entirely

Safety Notes

  • Assessed as safe for cosmetic use by expert review panels
  • Presents low risk of skin irritation in typical concentrations

Frequently Asked Questions about Sodium Polymethacrylate

What does Sodium Polymethacrylate do in products?

It thickens formulas, stabilizes emulsions, forms films, controls viscosity, binds ingredients, and adds opacity for better performance and aesthetics.

Is it safe for sensitive skin?

It shows low irritation potential and is regarded safe in cosmetics by regulatory reviews, though patch test if acrylate-sensitive.

Found in which skincare types?

Common in moisturizers, sunscreens, foundations, shampoos, and gels needing texture enhancement and stability.