Ingredient review
Lauroyl PEI-233/Polycaprolactone Copolymer
INCI: LAUROYL PEI-233/POLYCAPROLACTONE COPOLYMER
A film-forming polymer that helps products stay put longer and feel smoother, but it's not a star active ingredient.
In plain English
This ingredient is a type of plastic-like polymer that creates a thin, flexible film on your skin or hair. It's often added to makeup, sunscreens, and lotions to help them last longer, resist water, and feel silky. Think of it as a gentle glue that holds the product in place without clogging pores or causing irritation for most people.
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Lauroyl PEI-233/Polycaprolactone 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 Lauroyl PEI-233/Polycaprolactone 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 semi-synthetic copolymer made from lauric acid (a fatty acid from coconut or palm oil) and polycaprolactone (a biodegradable polyester). It's designed to form a smooth, flexible film on skin or hair.
How it works
When applied, the polymer molecules link together as the solvent evaporates, creating a thin, invisible film. This film helps other ingredients stay on the surface longer, reduces transfer (like from lipstick), and can improve water resistance in sunscreens.
Pros
Boosts wear time
Helps makeup and sunscreen stay put for hours, reducing the need for frequent touch-ups.
Improves texture
Creates a smooth, silky finish that can make products feel more luxurious on the skin.
Cons and cautions
Not a treatment ingredient
It doesn't hydrate, brighten, or treat skin concerns—it's purely a functional additive.
Potential tackiness
In high amounts, it can leave a slightly sticky or heavy feel, especially in humid conditions.
Best for
- Anyone wanting longer-lasting makeup or sunscreen
- People who prefer water-resistant sunscreens for swimming or sweating
Use caution if
- Those with very sensitive skin who react to film-formers (rare but possible)
Usage tips
Safety summary
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic potential, though individuals with very sensitive skin should patch-test products containing film-formers.
Research notes
Limited peer-reviewed studies on this specific copolymer, but related film-forming polymers have a long history of safe use in cosmetics. Safety assessments rely on analog data from similar ingredients.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. No specific restrictions at typical use levels.
- Common uses
- Long-wear makeup, Sunscreens, Water-resistant formulas
- Environmental note
- Polycaprolactone is biodegradable under industrial composting conditions, but environmental fate in water systems is less studied.
Good to know
- It's biodegradable due to the polycaprolactone component, making it more eco-friendly than some other film-formers.
- Often combined with silicones or oils to balance texture.
Common questions
What is Lauroyl PEI-233/Polycaprolactone Copolymer in beauty products?
This ingredient is a type of plastic-like polymer that creates a thin, flexible film on your skin or hair. It's often added to makeup, sunscreens, and lotions to help them last longer, resist water, and feel silky. Think of it as a gentle glue that holds the product in place without clogging pores or causing irritation for most people.
What does Lauroyl PEI-233/Polycaprolactone Copolymer do in a beauty product?
When applied, the polymer molecules link together as the solvent evaporates, creating a thin, invisible film. This film helps other ingredients stay on the surface longer, reduces transfer (like from lipstick), and can improve water resistance in sunscreens.
Is Lauroyl PEI-233/Polycaprolactone Copolymer safe for most people?
Considered safe for cosmetic use at typical concentrations. Low irritation and comedogenic potential, though individuals with very sensitive skin should patch-test products containing film-formers.
Who should be careful with Lauroyl PEI-233/Polycaprolactone Copolymer?
Those with very sensitive skin who react to film-formers (rare but possible)
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.