Ingredient review
Bis-HEMA IPDI/PEG-4 Copolymer
INCI: BIS-HEMA IPDI/PEG-4 COPOLYMER
A synthetic film-former that helps makeup last longer and resist water, but offers no skincare benefit.
In plain English
This ingredient is a plastic-like polymer that spreads into a thin, flexible film on your skin. It helps makeup stay put, resist sweat and water, and feel smooth. Think of it as a clear, invisible shield that keeps your foundation or mascara from smudging. It doesn't moisturize or treat skin—it's purely a performance enhancer for cosmetics.
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
Bis-HEMA IPDI/PEG-4 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 Bis-HEMA IPDI/PEG-4 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 created by reacting bis-HEMA (a methacrylate monomer), IPDI (isophorone diisocyanate), and PEG-4 (a short-chain polyethylene glycol). It belongs to the polyurethane family and is designed to form a durable, flexible film.
How it works
When applied, the copolymer's molecules link together as the solvent evaporates, forming a continuous, flexible film on the skin or lashes. This film physically locks pigments in place, resists water and oil, and reduces transfer to clothes or fingers.
Pros
Boosts makeup staying power
Creates a flexible film that locks in pigments, helping foundation, mascara, and lip products last through sweat, humidity, and daily activity.
Improves water resistance
Forms a barrier that repels water, making it ideal for waterproof mascaras and long-wear sunscreens that need to stay put at the beach or gym.
Cons and cautions
No skin benefits
This ingredient is purely functional—it doesn't hydrate, soothe, or protect skin. It's only there to improve product performance.
Can feel tight or heavy
On very sensitive or dry skin, the film may feel slightly tight or uncomfortable, especially if layered in multiple products.
Best for
- Anyone wanting long-wearing, waterproof makeup
- People with oily skin who struggle with makeup melting
Use caution if
- Those who prefer minimal, breathable makeup and dislike a film-like feel
Usage tips
Safety summary
Bis-HEMA IPDI/PEG-4 Copolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. However, as a synthetic film-former, it offers no skincare benefits and may feel drying to some users.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have reviewed similar polyurethane copolymers and found them safe for cosmetic use. Specific studies on this exact copolymer are limited, but its chemical class is well-tolerated.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics globally, including by the EU Cosmetics Regulation and the US FDA (as a cosmetic ingredient). No specific concentration limits are set, but typical use is low.
- Common uses
- Long-wear foundations, Waterproof mascaras, Lip products, Sunscreens
- Environmental note
- As a synthetic polymer, it is not biodegradable. However, it is used in small amounts and is not known to bioaccumulate significantly.
Good to know
- This ingredient is common in 'transfer-proof' and '24-hour wear' makeup claims.
- It is not water-soluble, so it won't rinse off with water alone.
Common questions
What is Bis-HEMA IPDI/PEG-4 Copolymer in beauty products?
This ingredient is a plastic-like polymer that spreads into a thin, flexible film on your skin. It helps makeup stay put, resist sweat and water, and feel smooth. Think of it as a clear, invisible shield that keeps your foundation or mascara from smudging. It doesn't moisturize or treat skin—it's purely a performance enhancer for cosmetics.
What does Bis-HEMA IPDI/PEG-4 Copolymer do in a beauty product?
When applied, the copolymer's molecules link together as the solvent evaporates, forming a continuous, flexible film on the skin or lashes. This film physically locks pigments in place, resists water and oil, and reduces transfer to clothes or fingers.
Is Bis-HEMA IPDI/PEG-4 Copolymer safe for most people?
Bis-HEMA IPDI/PEG-4 Copolymer is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential. However, as a synthetic film-former, it offers no skincare benefits and may feel drying to some users.
Who should be careful with Bis-HEMA IPDI/PEG-4 Copolymer?
Those who prefer minimal, breathable makeup and 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.