Ingredient review
Dilinoleic Acid Copolymer
INCI: DILINOLEIC ACID/SEBACIC ACID/PIPERAZINE/ETHYLENEDIAMINE COPOLYMER
A synthetic polymer that helps makeup and sunscreen stay put longer, but offers no direct skin benefit beyond its film-forming function.
In plain English
This is a plastic-like ingredient that creates a thin, flexible film on your skin. Think of it like a clear, invisible shield that helps your foundation or sunscreen resist sweat, water, and rubbing off onto clothes. It doesn't moisturize or treat your skin—it's purely a performance booster for the product.
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
Dilinoleic Acid 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 Dilinoleic Acid 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 made from dilinoleic acid, sebacic acid, piperazine, and ethylenediamine. It belongs to the polyamide family and is engineered to form a water-resistant film on the skin.
How it works
When applied, the polymer molecules link together to form a continuous, flexible film on the skin's surface. This film physically blocks water and oil from breaking down the product underneath, while also helping pigments and UV filters stay evenly distributed.
Pros
Boosts water resistance
Helps sunscreens and makeup stay effective longer when you sweat or swim, so you don't have to reapply as often.
Improves wear time
Foundations and mascaras with this polymer are less likely to smudge or fade during the day, reducing the need for touch-ups.
Cons and cautions
Can feel heavy
On oily or combination skin, the film may feel sticky or mask-like, especially in humid weather.
Requires double cleansing
Because it's water-resistant, you'll likely need an oil-based cleanser or micellar water to remove it fully, which adds a step to your routine.
Best for
- People who want long-wearing, waterproof makeup
- Those who need sunscreen that stays put during swimming or sweating
Use caution if
- Those with very oily or acne-prone skin who prefer lightweight, breathable formulas
Usage tips
Safety summary
Generally recognized as safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known systemic toxicity concerns from cosmetic use.
Research notes
Limited published studies specifically on this copolymer, but the broader class of polyamide film-formers has been reviewed by the CIR panel and found safe. Most evidence comes from manufacturer safety data and regulatory assessments.
Common label clues
- Typical concentration
- 1–10%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. The Cosmetic Ingredient Review (CIR) panel has evaluated similar polyamide polymers and found them safe at typical use concentrations.
- Common uses
- Sunscreens, Long-wear foundations, Waterproof mascaras, Lip products
- Environmental note
- As a synthetic polymer, it is not biodegradable and may contribute to microplastic pollution. Some brands are moving toward biodegradable film-formers as alternatives.
Good to know
- This ingredient is often listed near the end of an ingredient list because it's used in small amounts.
- It's considered safe for use in cosmetics by major regulatory bodies, but it's not biodegradable.
Common questions
What is Dilinoleic Acid Copolymer in beauty products?
This is a plastic-like ingredient that creates a thin, flexible film on your skin. Think of it like a clear, invisible shield that helps your foundation or sunscreen resist sweat, water, and rubbing off onto clothes. It doesn't moisturize or treat your skin—it's purely a performance booster for the product.
What does Dilinoleic Acid Copolymer do in a beauty product?
When applied, the polymer molecules link together to form a continuous, flexible film on the skin's surface. This film physically blocks water and oil from breaking down the product underneath, while also helping pigments and UV filters stay evenly distributed.
Is Dilinoleic Acid Copolymer safe for most people?
Generally recognized as safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known systemic toxicity concerns from cosmetic use.
Who should be careful with Dilinoleic Acid Copolymer?
Those with very oily or acne-prone skin who prefer lightweight, breathable formulas
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.