Ingredient review
PEG-16 Maleate/Styrene Sulfonate Copolymer
INCI: SODIUM METHOXY PEG-16 MALEATE/STYRENE SULFONATE COPOLYMER
A synthetic film-former that helps products stay put and resist water, but offers no active skincare benefit.
In plain English
This is a man-made polymer that creates a thin, flexible film on your skin or hair. Think of it like a clear, invisible shield that helps makeup last longer or sunscreen stay on when you sweat or swim. It doesn't moisturize or treat skin—it's purely a performance ingredient.
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
PEG-16 Maleate/Styrene Sulfonate 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 PEG-16 Maleate/Styrene Sulfonate 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 maleic acid and styrene sulfonate, modified with PEG (polyethylene glycol) to make it water-soluble and easy to formulate into cosmetics.
How it works
When applied, the polymer chains spread out and link together as the water evaporates, forming a continuous film on the skin or hair. This film helps other ingredients adhere better and resist being washed away by water or sweat.
Pros
Boosts water resistance
Helps sunscreens and makeup stay effective longer when you sweat or get wet, reducing the need for frequent reapplication.
Improves wear time
Creates a flexible film that keeps foundation and eye makeup from fading or creasing throughout the day.
Cons and cautions
No active skin benefit
This ingredient only improves product performance—it doesn't hydrate, soothe, or treat skin conditions.
Synthetic and not biodegradable
As a man-made polymer, it doesn't break down easily in the environment, which may be a concern for eco-conscious users.
Best for
- Anyone wanting longer-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 may find film-formers uncomfortable
- Anyone seeking purely natural or biodegradable ingredients
Usage tips
Safety summary
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic risk. No significant safety concerns reported in regulatory reviews.
Research notes
Limited peer-reviewed studies specific to this copolymer, but the class of PEG-modified maleate/styrene sulfonate polymers is well-established in cosmetics with a good safety profile. Regulatory bodies (FDA, EU SCCS) have not flagged concerns.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics globally, including by the U.S. FDA and EU CosIng database, with no known restrictions at typical concentrations.
- Common uses
- Sunscreens, Waterproof makeup, Long-wear foundations, Hair styling products
- Environmental note
- As a synthetic polymer, it is not readily biodegradable. However, it is used in small amounts and rinsed off, so its environmental impact is considered low compared to microplastics.
Good to know
- This ingredient is often found in 'waterproof' or 'long-wear' formulas, so check the label if you prefer easy removal.
- PEG compounds are purified during manufacturing to remove impurities, making them safe for cosmetic use at typical levels.
Common questions
What is PEG-16 Maleate/Styrene Sulfonate Copolymer in beauty products?
This is a man-made polymer that creates a thin, flexible film on your skin or hair. Think of it like a clear, invisible shield that helps makeup last longer or sunscreen stay on when you sweat or swim. It doesn't moisturize or treat skin—it's purely a performance ingredient.
What does PEG-16 Maleate/Styrene Sulfonate Copolymer do in a beauty product?
When applied, the polymer chains spread out and link together as the water evaporates, forming a continuous film on the skin or hair. This film helps other ingredients adhere better and resist being washed away by water or sweat.
Is PEG-16 Maleate/Styrene Sulfonate Copolymer safe for most people?
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic risk. No significant safety concerns reported in regulatory reviews.
Who should be careful with PEG-16 Maleate/Styrene Sulfonate Copolymer?
Those with very dry or dehydrated skin who may find film-formers uncomfortable Anyone seeking purely natural or biodegradable ingredients
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.