Ingredient review
Isophoronediamine Copolymer
INCI: ISOPHORONEDIAMINE/ISOPHTHALIC ACID/PENTAERYTHRITOL COPOLYMER
A synthetic film former that helps makeup and sunscreen stay put longer, but offers no active skincare benefits.
In plain English
This is a man-made polymer that forms a thin, flexible film on your skin or hair. Think of it like an invisible, breathable plastic wrap that helps other ingredients stay in place and resist water or sweat. It's commonly used in long-wear makeup and sunscreens to improve durability.
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
Isophoronediamine 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 Isophoronediamine 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 isophoronediamine, isophthalic acid, and pentaerythritol. 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 polymer molecules link together as the solvent (often water or alcohol) evaporates, forming a uniform, flexible film. This film physically locks in pigments, UV filters, or other active ingredients, improving their adherence and resistance to rubbing, water, and sweat.
Pros
Boosts wear time
Helps foundation and mascara stay put for hours without smudging or fading, even in humid conditions.
Water-resistant barrier
Creates a protective layer that resists water and sweat, making it ideal for waterproof sunscreens and active lifestyles.
Cons and cautions
Can feel tight
On dry or sensitive skin, the film may create a slight pulling or tightening sensation, especially if layered over multiple products.
Requires double cleansing
Because it forms a durable film, it may not rinse off with water alone and often needs an oil-based cleanser or micellar water for complete removal.
Best for
- Anyone wanting long-lasting makeup or sunscreen
- People with oily or combination skin who prefer a matte finish
Use caution if
- Those with very dry or dehydrated skin who may find film formers uncomfortable
Usage tips
Safety summary
Generally considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known systemic toxicity concerns from cosmetic use, as the polymer is too large to penetrate the skin.
Research notes
Limited peer-reviewed studies specifically on this copolymer, but the class of film-forming polymers is well-studied for safety and efficacy in cosmetics. Safety assessments rely on analog data from similar polymers reviewed by CIR and other bodies.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and other major markets. The Cosmetic Ingredient Review (CIR) panel has evaluated similar film-forming polymers and found them safe at typical use concentrations.
- Common uses
- Long-wear foundations, Waterproof mascaras, Sunscreens, Hair styling products
- Environmental note
- As a synthetic polymer, it is not biodegradable and may contribute to microplastic pollution if washed down drains. Some regions are beginning to regulate film-forming polymers for environmental reasons.
Good to know
- This polymer is not absorbed into the skin; it sits on the surface as a film.
- It is often combined with other film formers to fine-tune flexibility and durability.
Common questions
What is Isophoronediamine Copolymer in beauty products?
This is a man-made polymer that forms a thin, flexible film on your skin or hair. Think of it like an invisible, breathable plastic wrap that helps other ingredients stay in place and resist water or sweat. It's commonly used in long-wear makeup and sunscreens to improve durability.
What does Isophoronediamine Copolymer do in a beauty product?
When applied, the polymer molecules link together as the solvent (often water or alcohol) evaporates, forming a uniform, flexible film. This film physically locks in pigments, UV filters, or other active ingredients, improving their adherence and resistance to rubbing, water, and sweat.
Is Isophoronediamine Copolymer safe for most people?
Generally considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known systemic toxicity concerns from cosmetic use, as the polymer is too large to penetrate the skin.
Who should be careful with Isophoronediamine Copolymer?
Those with very dry or dehydrated skin who may find film formers uncomfortable
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.