What Is Acrylates/Steareth-20 Methacrylate Crosspolymer?
Acrylates/Steareth-20 Methacrylate Crosspolymer is a synthetic ingredient made by linking steareth-20 methacrylate with acrylic or methacrylic building blocks, then “cross-linking” the chains with small multifunctional molecules to form a three-dimensional network. The result is a lightweight powder that swells in water or other liquids to create clear, flexible films on the skin or hair. The technology grew out of the acrylic nail and paint industries of the 1970s, where durable yet flexible films were in high demand. Chemists adapted the same idea for skin care in the late 1990s when brands needed polymers that could hold modern, low-oil formulas together without feeling heavy or sticky. Today the ingredient is manufactured in closed reactors where the monomers are blended, polymerized, washed and dried before being milled to a fine powder. You will most often spot it in lightweight gels, sheet mask essences, anti-aging serums, leave-on hair treatments, sunscreens and long-wear makeup bases, where a clear film with a soft finish is useful.
Acrylates/Steareth-20 Methacrylate Crosspolymer’s Cosmetic Benefits/Uses
This ingredient is prized in formulations because it acts as a film former, meaning it creates an invisible layer that locks other ingredients in place.
As a film former Acrylates/Steareth-20 Methacrylate Crosspolymer helps products glide on smoothly, then sets to form a breathable shield that reduces moisture loss, improves the wear time of makeup and keeps active ingredients such as antioxidants or sunscreens exactly where you want them. The flexible film also gives hair products light hold without crunch and lends skin care a soft, silky finish that resists smudging or pilling under additional layers.
Who Can Use Acrylates/Steareth-20 Methacrylate Crosspolymer
This film-forming polymer is generally well tolerated by all skin types. Its lightweight, non-greasy nature suits oily and combination skin, while the flexible shield it creates helps prevent water loss, making it comfortable for normal and mildly dry skin too. Very dry skin may still need a richer cream on top for added occlusion, and highly sensitive or eczema-prone users should stay alert if they know they react to acrylics in nail products or adhesives.
Acrylates/Steareth-20 Methacrylate Crosspolymer is made entirely from synthetic raw materials, so it contains no animal-derived substances. As a result it is considered appropriate for vegetarians and vegans.
No data suggest any risk to women who are pregnant or breastfeeding when the ingredient is used topically in cosmetics. It forms an external film and is not known to penetrate the skin to any meaningful degree. This is not medical advice; anyone who is pregnant or nursing should run any skincare product past a qualified healthcare professional just to be on the safe side.
The polymer itself is not photosensitising, so it will not make skin more prone to sunburn. In fact it is often paired with UV filters to help them stay in place. Aside from the rare chance of an acrylic allergy, it is broadly compatible with most other cosmetic ingredients and routines.
Potential Side Effects/Adverse Reactions
Responses to topical Acrylates/Steareth-20 Methacrylate Crosspolymer can vary from person to person. The effects listed below are only potential outcomes and are unlikely for most users when the ingredient is used correctly in a well-formulated product.
- Contact dermatitis in individuals already sensitised to acrylic or methacrylate compounds
- Mild skin tightness or transient dryness if the formula lacks additional humectants or emollients
- Temporary eye irritation if the product accidentally gets into the eyes
- Build-up or a slight film on hair with very frequent use in styling products
If you notice redness, itching or any other persistent discomfort while using a product that contains this polymer, stop using it and consult a healthcare professional for personalized guidance.
Comedogenic Rating
Rating: 1/5
Acrylates/Steareth-20 Methacrylate Crosspolymer forms a lightweight breathable film that sits on top of the skin rather than soaking into pores. It is a large synthetic molecule that is not oily and is rinsed away easily, so the chance of it blocking pores is very low. For this reason formulators usually treat it as practically non-comedogenic.
Suitable for acne-prone or breakout-prone skin in most cases.
Because the polymer is often paired with silicones or waxes that can vary in their pore-clogging potential, the overall formula still matters. Always check the whole ingredient list if you are highly clog-prone.
Summary
Acrylates/Steareth-20 Methacrylate Crosspolymer is a film former that helps skin care, hair care and makeup stay put, feel smoother and lose less water. It does this by swelling in the formula then drying into an invisible flexible layer that anchors pigments, UV filters and other actives where you apply them.
While not a household name, the polymer has carved out a steady niche in gels, serums, sunscreens and long-wear cosmetics because it offers hold without heaviness and plays nicely with modern low-oil formulas.
Safety data and decades of cosmetic use show it is low risk for most people, with acrylic allergy being the main rare concern. As with any new product, patch test first so you can be sure your skin agrees with the full formula.