What Is Acrylates/Ceteth-20 Methacrylate Copolymer?
Acrylates/Ceteth-20 Methacrylate Copolymer is a synthetic ingredient made by linking together small units of methacrylic acid with Ceteth-20, a fatty alcohol-based surfactant, and other acrylic building blocks. The result is a large, water-loving molecule that swells in water and helps give products the right thickness. Chemists first introduced this copolymer in the late 1980s when cosmetic brands wanted lighter, smoother alternatives to heavy waxes for gels and lotions. Production involves controlled polymerization where the monomers are mixed, heated, and reacted under strict conditions, then purified and dried into a fine powder or pre-neutralized liquid. You will most often find it in face and body lotions, moisturizers, sunscreens, serums, sheet mask essences, hair gels, styling creams, and some mascara or brow formulas where a clean, non-sticky feel is desired.
Acrylates/Ceteth-20 Methacrylate Copolymer’s Cosmetic Benefits/Uses
This ingredient plays one key role in a formula.
As a viscosity controlling agent it helps set the thickness of a product so it feels neither too runny nor too heavy. By swelling in water it keeps emulsions stable, stops ingredients from separating, and gives creams and gels a smooth, spreadable texture that users enjoy. Stable viscosity also helps actives stay evenly distributed, which supports consistent performance with every application.
Who Can Use Acrylates/Ceteth-20 Methacrylate Copolymer
This polymer is generally well tolerated by all skin types, including oily, combination, dry and sensitive skin, because it mainly acts on texture rather than on the skin itself. People with very reactive or allergy-prone skin should still keep an eye on the ingredient list, but most users experience no problems. As a fully synthetic material it contains no animal derivatives, so it is suitable for vegans and vegetarians provided the finished product has not been tested on animals. Current safety assessments have found no reproductive or developmental concerns, meaning that pregnant or breastfeeding individuals can usually use products containing this copolymer; however this is not medical advice and anyone who is pregnant or nursing should show the full product lineup to their doctor first. The ingredient does not make skin more sensitive to sunlight and it does not interfere with common actives like vitamin C or retinoids, so daytime use is fine.
Potential Side Effects/Adverse Reactions
Side effects or reactions to topical Acrylates/Ceteth-20 Methacrylate Copolymer differ from person to person. The points below describe potential issues and are unlikely to occur in most users, assuming the product is formulated correctly.
- Mild skin redness or itching in individuals who are sensitive to acrylic polymers
- Rare cases of allergic contact dermatitis
- Temporary eye stinging if a formula containing the copolymer gets into the eyes
- Build-up or flaking on hair when used in high-hold styling products
If any of these reactions appear stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0–1 (very low)
Acrylates/Ceteth-20 Methacrylate Copolymer is a large, water-soluble molecule that stays on the skin’s surface and does not dissolve in skin oils or clog pores. It is usually present at low amounts and is often part of lightweight, oil-free gels, so the chance of it trapping sebum is minimal. For these reasons the comedogenic potential is considered negligible.
Suitable for acne-prone or breakout-prone skin.
Only if a formula also contains heavy oils or waxes could pore clogging become an issue, but that would be due to those other ingredients, not the copolymer itself.
Summary
Acrylates/Ceteth-20 Methacrylate Copolymer is a texture fixer. It swells in water, thickens emulsions and keeps creams, gels and sprays from separating so every pump or scoop feels consistent. You will spot it in moisturizers, sunscreens, hair gels and some color cosmetics where chemists want a smooth, non-sticky glide.
While useful it is less famous than workhorse polymers like carbomer, so it appears in a moderate number of products rather than in everything on the shelf.
Current safety reviews rate it as low risk with few reported irritations. Still, everyone’s skin is unique so do a quick patch test when trying any new product containing this ingredient just to be safe.