Ingredient review
Dimer Dilinoleic Copolymer
INCI: Bis-Dioctadecylamide Dimer Dilinoleic Acid/Ethylenediamine Copolymer
A synthetic film-former that helps products stay put and resist water, but offers no active skincare benefits.
In plain English
This ingredient is a synthetic polymer that creates a thin, flexible film on your skin or hair. Think of it like a clear, invisible shield that helps makeup or sunscreen stay in place longer and resist water or sweat. It doesn't moisturize or treat your skin—it's purely a texture and performance helper.
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
Dimer Dilinoleic 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 Dimer Dilinoleic 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 large synthetic molecule made by linking dimer dilinoleic acid (a fatty acid derivative) with ethylenediamine and long-chain amides. It belongs to a class of ingredients called film-formers.
How it works
When applied, the polymer chains spread out and then link together as the solvent evaporates, forming a continuous, flexible film. This film physically blocks water and oil from disturbing the product underneath, improving wear time and water resistance.
Pros
Boosts water resistance
Helps sunscreen and makeup stay effective even when you sweat or swim, so you don't have to reapply as often.
Improves wear time
Creates a flexible film that keeps foundation or mascara from smudging or fading throughout the day.
Cons and cautions
No active benefits
This ingredient only provides texture and film-forming properties—it won't hydrate, soothe, or protect your skin from aging or irritation.
Can feel heavy
On dry or sensitive skin, the film may feel tight or uncomfortable, especially if layered under multiple products.
Best for
- People who need long-wearing or waterproof makeup and sunscreen
- Those with oily or combination skin who want a matte, stay-put finish
Use caution if
- Anyone with very dry or sensitive skin who prefers lightweight, breathable formulas
Usage tips
Safety summary
Considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known toxicity or sensitization in cosmetic use.
Research notes
Limited independent studies on this specific polymer. Safety is inferred from its chemical class and long history of use in cosmetics. No major safety concerns reported.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and other major markets. No specific concentration limits are set, but typical use is low.
- Common uses
- Sunscreens, Waterproof mascara, Long-wear foundations
- Environmental note
- As a synthetic polymer, it may not be biodegradable. Check product labels for eco-friendly claims if this is a concern.
Good to know
- This ingredient is often found in 'waterproof' or 'long-wear' labeled products.
- It is not a humectant or emollient, so it won't add moisture to your skin.
Common questions
What is Dimer Dilinoleic Copolymer in beauty products?
This ingredient is a synthetic polymer that creates a thin, flexible film on your skin or hair. Think of it like a clear, invisible shield that helps makeup or sunscreen stay in place longer and resist water or sweat. It doesn't moisturize or treat your skin—it's purely a texture and performance helper.
What does Dimer Dilinoleic Copolymer do in a beauty product?
When applied, the polymer chains spread out and then link together as the solvent evaporates, forming a continuous, flexible film. This film physically blocks water and oil from disturbing the product underneath, improving wear time and water resistance.
Is Dimer Dilinoleic Copolymer safe for most people?
Considered safe for topical use at typical concentrations. Low irritation and comedogenic risk. No known toxicity or sensitization in cosmetic use.
Who should be careful with Dimer Dilinoleic Copolymer?
Anyone with very dry or sensitive skin who prefers 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.