Ingredient review
Isophorone Diamine Copolymer
INCI: ISOPHORONE DIAMINE/ISOPHTHALIC ACID/TROMETHAMINE COPOLYMER
A synthetic film-former that helps products stay put, but offers no active skincare benefit.
In plain English
This is a man-made polymer that dries down to form a thin, flexible film on your skin or hair. Think of it like an invisible, breathable plastic wrap that helps makeup last longer or holds a hairstyle in place. It's not an active ingredient that improves your skin; it's a helper ingredient that improves 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
Isophorone Diamine 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 Isophorone Diamine 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 isophorone diamine, isophthalic acid, and tromethamine. It belongs to the polyamide family and is designed to form a durable yet flexible film.
How it works
When applied, the copolymer's molecules link together as the solvent (water or alcohol) evaporates, creating a continuous, water-resistant layer. This film adheres to the skin or hair, locking in pigments or styling hold while allowing some flexibility to prevent cracking.
Pros
Boosts product longevity
Creates a flexible film that helps makeup and sunscreen resist water, sweat, and rubbing, so you need fewer touch-ups.
Low irritation potential
Generally well-tolerated on skin, with a low risk of irritation or clogging pores, making it suitable for sensitive skin in small amounts.
Cons and cautions
No skin benefit
This ingredient does not hydrate, soothe, or repair skin—it's purely a cosmetic film-former that improves product feel and wear.
Removal can be tricky
Because it forms a water-resistant layer, you may need an oil-based or micellar cleanser to fully remove it, especially from eye makeup.
Best for
- Anyone wanting long-lasting, water-resistant makeup or sunscreen
- People with normal to dry skin who don't mind a slight film feel
Use caution if
- Those who prefer minimal, lightweight formulas with few synthetic additives
Usage tips
Safety summary
Isophorone Diamine/Isophthalic Acid/Tromethamine Copolymer is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. No significant safety concerns have been reported in regulatory reviews.
Research notes
There is limited published research specifically on this copolymer, but it is structurally similar to other polyamide film-formers that have been evaluated for safety by cosmetic ingredient review panels. Its safety profile is supported by its widespread use and low reported irritation.
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 known restrictions at typical use levels.
- Common uses
- Sunscreens, Waterproof mascaras, Long-wear foundations, Hair styling products
- Environmental note
- As a synthetic polymer, it is not biodegradable. However, it is used in small amounts and is not considered a major environmental concern compared to microplastics.
Good to know
- This polymer is often used in 'clean' or 'mineral' sunscreens to improve water resistance without chemical UV filters.
- It is not absorbed into the skin; it stays on the surface and is washed off with cleansing.
Common questions
What is Isophorone Diamine Copolymer in beauty products?
This is a man-made polymer that dries down to form a thin, flexible film on your skin or hair. Think of it like an invisible, breathable plastic wrap that helps makeup last longer or holds a hairstyle in place. It's not an active ingredient that improves your skin; it's a helper ingredient that improves product performance.
What does Isophorone Diamine Copolymer do in a beauty product?
When applied, the copolymer's molecules link together as the solvent (water or alcohol) evaporates, creating a continuous, water-resistant layer. This film adheres to the skin or hair, locking in pigments or styling hold while allowing some flexibility to prevent cracking.
Is Isophorone Diamine Copolymer safe for most people?
Isophorone Diamine/Isophthalic Acid/Tromethamine Copolymer is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. No significant safety concerns have been reported in regulatory reviews.
Who should be careful with Isophorone Diamine Copolymer?
Those who prefer minimal, lightweight formulas with few synthetic additives
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.