Ingredient review
PEI-275
INCI: PEI-275
PEI-275 is a synthetic polymer that helps products form a flexible film on skin or hair, improving wear and water resistance.
In plain English
PEI-275 is a man-made ingredient that creates a thin, flexible film when applied to skin or hair. Think of it like a clear, invisible coating that helps makeup stay put longer or helps hair hold its shape. It's not an active skincare ingredient—it's more of a helper that improves how a product feels and performs.
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
PEI-275 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 PEI-275.
- 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
PEI-275 is a synthetic polymer derived from polyethyleneimine. It is a water-soluble, cationic (positively charged) substance that binds to surfaces and forms a film upon drying.
How it works
When applied, PEI-275 molecules spread evenly and then link together as the water evaporates, creating a continuous, flexible film. This film helps other ingredients (like pigments in mascara) adhere better and resist smudging or running. In hair products, it can provide light hold and reduce frizz by coating each strand.
Pros
Long-lasting wear
PEI-275 helps makeup and hair products resist smudging, flaking, and fading throughout the day, so you need fewer touch-ups.
Flexible film
Unlike some stiff polymers, PEI-275 creates a film that moves with your skin or hair, reducing the chance of cracking or flaking.
Cons and cautions
Potential tackiness
If used at too high a concentration, PEI-275 can leave a slightly sticky or stiff feel on skin or hair, which some people find uncomfortable.
Buildup risk
Frequent use in hair products may lead to buildup over time, making hair feel heavy or look dull unless clarified regularly.
Best for
- People who want long-wearing makeup like mascara or eyeliner
- Those looking for a light-hold hair product without heavy residue
Use caution if
- Individuals with very sensitive or reactive skin (patch test recommended)
- Those who prefer only natural or plant-based ingredients
Usage tips
Safety summary
PEI-275 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, but individuals with very sensitive skin should patch test first. Long-term safety data is limited but no major concerns have been raised by regulatory bodies.
Research notes
Research on PEI-275 specifically in cosmetics is sparse. However, similar polyethyleneimine polymers have been studied for their film-forming and adhesive properties. No peer-reviewed studies on cosmetic safety or efficacy were found in major databases.
Common label clues
- Typical concentration
- Typically used at 0.1–2% in rinse-off or leave-on formulas
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. No specific concentration limits are set, but manufacturers follow good manufacturing practices.
- Common uses
- Mascaras, Eyeliners, Setting Sprays, Hair Styling Products
- Environmental note
- As a synthetic polymer, PEI-275 is not biodegradable. Its environmental impact depends on how it is formulated and disposed of.
Good to know
- PEI-275 is often used in 'tubing' mascaras that form tiny tubes around lashes for easy removal with warm water.
- It is not a preservative, fragrance, or active skincare ingredient—it's purely a performance enhancer.
Common questions
What is PEI-275 in beauty products?
PEI-275 is a man-made ingredient that creates a thin, flexible film when applied to skin or hair. Think of it like a clear, invisible coating that helps makeup stay put longer or helps hair hold its shape. It's not an active skincare ingredient—it's more of a helper that improves how a product feels and performs.
What does PEI-275 do in a beauty product?
When applied, PEI-275 molecules spread evenly and then link together as the water evaporates, creating a continuous, flexible film. This film helps other ingredients (like pigments in mascara) adhere better and resist smudging or running. In hair products, it can provide light hold and reduce frizz by coating each strand.
Is PEI-275 safe for most people?
PEI-275 is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, but individuals with very sensitive skin should patch test first. Long-term safety data is limited but no major concerns have been raised by regulatory bodies.
Who should be careful with PEI-275?
Individuals with very sensitive or reactive skin (patch test recommended) Those who prefer only natural or plant-based 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.