Acrylates/Stearyl Methacrylate Copolymer
Synthetic copolymer. Thickens emulsions and forms a soft film on the skin – gives makeup long wear and helps foundations resist transfer. In skincare appears in sunscreens and primers. The molecule is large and does not penetrate skin.
Supporting ingredient
It gives a product its texture, stability or shelf life. It has no claimed effect on the skin, so an efficacy tier does not apply. What is known about its safety is below
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Oily, Sensitive
About this ingredient
Acrylates/Stearyl Methacrylate Copolymer is a synthetic copolymer based on acrylates and stearyl methacrylate (a long C18 chain from stearic acid). The long hydrophobic side chain gives the polymer film-forming and thickening properties. Mechanism. In formula, it acts as a thickener and emulsion stabilizer: builds a 3D network, raises viscosity, keeps pigments suspended. On skin it forms a soft hydrophobic film that holds color and UV filter in place. Where applied. Foundations, BB creams, primers, water-resistant makeup, tinted sunscreens. Concentration 0.5–3%. Common in Maybelline, MAC, La Roche-Posay Anthelios Anti-Imperfections (tinted). Safety. CIR confirmed safety of acrylate copolymers in cosmetics. The molecule is large, does not cross the epidermis, does not enter circulation. Hypoallergenic, non-irritating. Pregnancy and lactation – safe. Acceptable at any stage, including foundations and sunscreens marked 'safe for pregnancy'. Environmental controversy. Like Acrylates Copolymer, this is a synthetic insoluble polymer. EU Regulation 2023/2055 restricts intentionally added microplastics in leave-on cosmetics from 2027. Functional role. No standalone skin benefit – a formula structurant.
Frequently asked questions
Is Acrylates/Stearyl Methacrylate Copolymer safe during pregnancy?
Acrylates/Stearyl Methacrylate Copolymer is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Acrylates/Stearyl Methacrylate Copolymer for?
Acrylates/Stearyl Methacrylate Copolymer suits: normal, dry, combination, oily, sensitive.
What is Acrylates/Stearyl Methacrylate Copolymer and what does it do in cosmetics?
Synthetic copolymer.
What's the INCI name for Acrylates/Stearyl Methacrylate Copolymer?
The INCI name is Acrylates/Stearyl Methacrylate Copolymer. It may also appear as: Acrylate Copolymer.
See Acrylates/Stearyl Methacrylate Copolymer in a product composition right on the store page
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Similar role in the formula
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