Ingredient review
Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate Copolymer
INCI: DIISOPROPANOLAMINE/METHYLHEXAHYDROPHTHALIC ANHYDRIDE ETHYLHEXANOATE COPOLYMER
A synthetic polymer that helps products stay put and resist water, but offers no active skincare benefit.
In plain English
This is a man-made ingredient that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable raincoat—it helps sunscreen or makeup stay in place longer and resist sweat or water. It doesn't moisturize or treat your skin; it's purely a helper ingredient for product performance.
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
Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate 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 Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate 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 diisopropanolamine with a modified phthalic anhydride and ethylhexanoate. It belongs to a class of ingredients called film formers, which are designed to create a continuous layer on the skin or hair surface.
How it works
When applied, the copolymer molecules link together as the solvent evaporates, forming a flexible, invisible film. This film physically locks in other ingredients (like sunscreen filters or pigments) and provides water resistance. It also helps reduce transfer of makeup to clothing or surfaces.
Pros
Boosts water resistance
Helps sunscreens and makeup stay effective longer during swimming, sweating, or humid conditions.
Reduces makeup transfer
Creates a flexible barrier that keeps foundation and tinted products from rubbing off on masks, phones, or clothing.
Cons and cautions
No skincare benefit
This ingredient does not moisturize, soothe, or repair skin—it only improves product performance.
May feel tight on dry skin
The film can create a slight pulling sensation, especially if your skin is already dehydrated or sensitive.
Best for
- People who want long-lasting, water-resistant sunscreen or makeup
- Those with oily skin who prefer a matte, stay-put finish
Use caution if
- Individuals with very dry or compromised skin barriers who may find film formers too occlusive
Usage tips
Safety summary
Considered safe for use in cosmetics at typical concentrations. Low irritation and comedogenic risk. No known significant health concerns, though individuals with very sensitive skin may experience mild tightness.
Research notes
Limited independent research on this specific copolymer, but it is structurally similar to other widely used film-forming polymers that have been reviewed as safe by cosmetic ingredient safety panels (e.g., CIR).
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 biodegradable and may contribute to microplastic pollution. Some regions are beginning to restrict certain film-forming polymers for environmental reasons.
Good to know
- This ingredient is not water-soluble, so double cleansing is recommended for removal.
- It is commonly found in 'sport' or 'water-resistant' sunscreen formulas.
Common questions
What is Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate Copolymer in beauty products?
This is a man-made ingredient that forms a thin, flexible film on your skin or hair. Think of it like a clear, breathable raincoat—it helps sunscreen or makeup stay in place longer and resist sweat or water. It doesn't moisturize or treat your skin; it's purely a helper ingredient for product performance.
What does Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate Copolymer do in a beauty product?
When applied, the copolymer molecules link together as the solvent evaporates, forming a flexible, invisible film. This film physically locks in other ingredients (like sunscreen filters or pigments) and provides water resistance. It also helps reduce transfer of makeup to clothing or surfaces.
Is Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate Copolymer safe for most people?
Considered safe for use in cosmetics at typical concentrations. Low irritation and comedogenic risk. No known significant health concerns, though individuals with very sensitive skin may experience mild tightness.
Who should be careful with Diisopropanolamine/Methylhexahydrophthalic Anhydride Ethylhexanoate Copolymer?
Individuals with very dry or compromised skin barriers who may find film formers too occlusive
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.