Ingredient review
Butyl Methacrylate Copolymer
INCI: Butyl Methacrylate/Acryloyloxy PG Methacrylate Copolymer
A synthetic film-former that helps makeup and skincare last longer without clogging pores or causing irritation for most people.
In plain English
This is a synthetic polymer that creates a thin, flexible film on your skin or hair. Think of it like an invisible, breathable shield that helps makeup stay put, sunscreen resist water, or lotion feel smooth without being sticky. It's a common ingredient in long-wear and waterproof products.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Butyl 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging Butyl Methacrylate Copolymer.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic copolymer made from butyl methacrylate and a modified methacrylate monomer. It belongs to the acrylate family of film-forming polymers widely used in cosmetics.
How it works
When the product dries, the polymer molecules link together to form a continuous, flexible film on the skin or hair. This film locks in pigments and other ingredients, improves water resistance, and can also help control the feel and spreadability of the formula.
Pros
Boosts wear time
Helps foundation, mascara, and lip products stay put for hours without smudging or fading.
Water-resistant
Creates a barrier that resists water and sweat, making it ideal for active lifestyles or humid climates.
Cons and cautions
Synthetic origin
Made from petrochemicals, which may not align with natural or minimalist skincare preferences.
Potential tightness
In high concentrations, the film can feel slightly tight or dry on very dry or sensitive skin.
Best for
- Anyone wanting long-wear or waterproof makeup
- People with oily or combination skin who need extra staying power
Use caution if
- Those who prefer 100% natural or plant-based formulas
- Individuals with known acrylate allergies (rare)
Usage tips
Safety summary
Considered safe for cosmetic use at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has evaluated similar acrylate copolymers and found them safe when formulated properly. Rare allergic reactions are possible in individuals sensitive to acrylates.
Research notes
Safety data for this specific copolymer is limited, but the broader class of acrylate copolymers has been reviewed by the CIR and deemed safe. No significant irritation or sensitization was observed in standard tests.
Common label clues
- Typical concentration
- Typically 1–10% in leave-on formulas
- Regulatory status
- Approved for use in cosmetics globally, including by the U.S. FDA and EU CosIng database, with no known restrictions at typical use levels.
- Common uses
- Long-wear foundations, Waterproof mascaras, Sunscreens, Lip products
- Environmental note
- As a synthetic polymer, it is not biodegradable. However, it is used in small amounts and is not considered a major environmental concern compared to microplastics.
Good to know
- This ingredient is not absorbed into the skin — it stays on the surface to form its protective film.
- It is often combined with other film-formers to fine-tune the feel and flexibility of the final product.
Common questions
What is Butyl Methacrylate Copolymer in beauty products?
This is a synthetic polymer that creates a thin, flexible film on your skin or hair. Think of it like an invisible, breathable shield that helps makeup stay put, sunscreen resist water, or lotion feel smooth without being sticky. It's a common ingredient in long-wear and waterproof products.
What does Butyl Methacrylate Copolymer do in a beauty product?
When the product dries, the polymer molecules link together to form a continuous, flexible film on the skin or hair. This film locks in pigments and other ingredients, improves water resistance, and can also help control the feel and spreadability of the formula.
Is Butyl Methacrylate Copolymer safe for most people?
Considered safe for cosmetic use at typical concentrations. The Cosmetic Ingredient Review (CIR) panel has evaluated similar acrylate copolymers and found them safe when formulated properly. Rare allergic reactions are possible in individuals sensitive to acrylates.
Who should be careful with Butyl Methacrylate Copolymer?
Those who prefer 100% natural or plant-based formulas Individuals with known acrylate allergies (rare)
Research sources
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.