Ingredient review
Butyldimethicone Methacrylate Crosspolymer
INCI: Butyldimethicone Methacrylate/Methyl Methacrylate Crosspolymer
A silicone-based film former that improves wear time and water resistance without feeling heavy or sticky.
In plain English
This ingredient is a synthetic polymer made from silicone and acrylic building blocks. When applied to skin, it dries down to form a flexible, invisible film that helps makeup and skincare stay put longer, resist water and sweat, and feel smooth to the touch. It's commonly used 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
Butyldimethicone Methacrylate Crosspolymer 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 Butyldimethicone Methacrylate Crosspolymer.
- 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 crosslinked silicone-acrylate copolymer, meaning it's a large molecule created by linking silicone and acrylic units together. It is designed to form a breathable, flexible film on the skin or hair.
How it works
After the product is applied and the solvent (usually water or alcohol) evaporates, the polymer chains link together into a continuous film. This film acts as a barrier that locks in pigments and active ingredients, reduces transfer, and provides a silky, non-greasy feel.
Pros
Long-lasting wear
Helps makeup and sunscreen stay in place for hours, even in humid or sweaty conditions.
Smooth texture
Imparts a silky, non-greasy finish that makes products glide on easily and feel lightweight.
Cons and cautions
Can feel tight
On very dry skin, the film may create a slight tightening sensation, which some find uncomfortable.
Requires double cleansing
Because it forms a water-resistant film, it may not rinse off with water alone and often needs an oil-based cleanser for complete removal.
Best for
- Anyone wanting long-lasting makeup or water-resistant sunscreen
- People with oily or combination skin who prefer a matte finish
Use caution if
- Those with very dry or dehydrated skin who dislike a film-like feel
Usage tips
Safety summary
Butyldimethicone Methacrylate/Methyl Methacrylate Crosspolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, though individuals with very sensitive or dry skin may notice a slight tightening sensation.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that similar silicone acrylate copolymers are safe when formulated to be non-irritating. No significant human or animal toxicity data specific to this exact polymer is available, but its large molecular size limits skin penetration.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics globally, including by the U.S. FDA and EU CosIng database, with no concentration restrictions.
- Common uses
- Long-wear foundations, Waterproof mascara, Sunscreens, Primers, Lip products
- Environmental note
- As a synthetic silicone-based polymer, it is not biodegradable. However, it is used in low concentrations and is not known to bioaccumulate significantly.
Good to know
- This ingredient is considered non-comedogenic for most skin types.
- It is often combined with other silicones to fine-tune the feel and durability of a formula.
Common questions
What is Butyldimethicone Methacrylate Crosspolymer in beauty products?
This ingredient is a synthetic polymer made from silicone and acrylic building blocks. When applied to skin, it dries down to form a flexible, invisible film that helps makeup and skincare stay put longer, resist water and sweat, and feel smooth to the touch. It's commonly used in long-wear and waterproof products.
What does Butyldimethicone Methacrylate Crosspolymer do in a beauty product?
After the product is applied and the solvent (usually water or alcohol) evaporates, the polymer chains link together into a continuous film. This film acts as a barrier that locks in pigments and active ingredients, reduces transfer, and provides a silky, non-greasy feel.
Is Butyldimethicone Methacrylate Crosspolymer safe for most people?
Butyldimethicone Methacrylate/Methyl Methacrylate Crosspolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, though individuals with very sensitive or dry skin may notice a slight tightening sensation.
Who should be careful with Butyldimethicone Methacrylate Crosspolymer?
Those with very dry or dehydrated skin who dislike a film-like feel
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.