Ingredient review

Acrylates/Stearyl Methacrylate Copolymer

INCI: ACRYLATES/STEARYL METHACRYLATE COPOLYMER

A synthetic film-former that helps products stay put and resist water, but may feel slightly tight or heavy on some skin types.

beautyskincarefilm-former

In plain English

This ingredient is a synthetic polymer that forms a thin, flexible film on the skin or hair. Think of it like a clear, invisible shield that helps makeup or sunscreen stay in place longer and resist water or sweat. It's commonly used in products that need to be long-lasting, such as waterproof mascara or all-day foundation. While it's generally safe and non-irritating, the film it creates can sometimes feel a bit tight or heavy, especially on dry or sensitive skin.

Quick decision guide

Useful, but context matters

Acrylates/Stearyl Methacrylate Copolymer is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Acrylates/Stearyl Methacrylate Copolymer.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A synthetic copolymer made from acrylic acid derivatives and stearyl methacrylate, designed to create a flexible, water-resistant film on the skin or hair.

How it works

When applied, the polymer molecules link together as the product dries, forming a continuous, invisible film. This film helps lock in other ingredients, improves water resistance, and prevents makeup from smudging or fading. It also adds a slight thickening effect to the product's texture.

Pros

Long-lasting wear

Helps makeup and sunscreen stay put for hours, reducing the need for touch-ups.

Water resistance

Creates a barrier that resists water and sweat, ideal for swimming or hot weather.

Cons and cautions

Potential tightness

The film can feel slightly tight or heavy on dry or sensitive skin, which some find uncomfortable.

Removal difficulty

May require an oil-based or dual-phase cleanser to fully remove, especially from waterproof products.

Best for

  • People who want long-lasting makeup or sunscreen
  • Those who need water-resistant products for outdoor activities or humid climates

Use caution if

  • Individuals with very dry or sensitive skin who find film-formers uncomfortable
  • Those who prefer lightweight, breathable formulas

Usage tips

Use a gentle oil-based cleanser or micellar water to thoroughly remove products containing this polymer.
If you have dry skin, layer a hydrating moisturizer underneath to minimize any tight feeling.

Safety summary

Acrylates/Stearyl Methacrylate Copolymer is considered safe for cosmetic use with low irritation and comedogenic potential. It is not known to be toxic or sensitizing at typical concentrations.

Research notes

Evidence is based on industry safety assessments and regulatory approvals. No significant peer-reviewed studies highlight safety concerns, but long-term environmental impact is an area of ongoing discussion.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the US, EU, and other major markets. Generally recognized as safe at typical concentrations.
Common uses
Sunscreens, Waterproof mascaras, Long-wear foundations, Lip products
Environmental note
As a synthetic polymer, it is not biodegradable and may contribute to microplastic pollution. Some manufacturers are exploring bio-based alternatives.

Good to know

  • This ingredient is often found in combination with other film-formers to enhance performance.
  • It is considered safe by major cosmetic regulatory bodies when used as directed.

Common questions

What is Acrylates/Stearyl Methacrylate Copolymer in beauty products?

This ingredient is a synthetic polymer that forms a thin, flexible film on the skin or hair. Think of it like a clear, invisible shield that helps makeup or sunscreen stay in place longer and resist water or sweat. It's commonly used in products that need to be long-lasting, such as waterproof mascara or all-day foundation. While it's generally safe and non-irritating, the film it creates can sometimes feel a bit tight or heavy, especially on dry or sensitive skin.

What does Acrylates/Stearyl Methacrylate Copolymer do in a beauty product?

When applied, the polymer molecules link together as the product dries, forming a continuous, invisible film. This film helps lock in other ingredients, improves water resistance, and prevents makeup from smudging or fading. It also adds a slight thickening effect to the product's texture.

Is Acrylates/Stearyl Methacrylate Copolymer safe for most people?

Acrylates/Stearyl Methacrylate Copolymer is considered safe for cosmetic use with low irritation and comedogenic potential. It is not known to be toxic or sensitizing at typical concentrations.

Who should be careful with Acrylates/Stearyl Methacrylate Copolymer?

Individuals with very dry or sensitive skin who find film-formers uncomfortable Those who prefer lightweight, breathable formulas

Research sources

Cosmetic Ingredient Review (CIR) Safety AssessmentOpenEuropean Chemicals Agency (ECHA) DatabaseOpenPersonal Care Products Council - Ingredient DatabaseOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.