What Is Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer?
Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer is a man-made polymer created by reacting three building blocks: adipic acid, neopentyl glycol and trimellitic anhydride. The result is a large, stable molecule that forms a flexible film when it dries on the skin or hair. This ingredient is sourced from basic petrochemical feedstocks that are refined then combined under heat and pressure in controlled factory settings. The process links the three raw materials into long chains, producing a clear resin that is later ground into a fine powder or dispersed in liquid for easy use in cosmetic labs.
The cosmetic world began adopting this polymer in the late 1990s as formulators searched for lightweight film formers that could resist water yet feel comfortable on the skin. Its ability to stay put without a sticky feel made it attractive for many modern beauty products.
Today you will most often find Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer in color cosmetics such as mascaras, eyeliners, liquid lipsticks and foundations. It also appears in some sunscreens, setting sprays, long-wear skin tints, peel-off masks and hair styling products where a flexible, breathable coating is needed.
Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer’s Cosmetic Benefits/Uses
This ingredient offers one key function in cosmetics: film forming. As a film former it creates a thin, even layer over skin, lashes or hair that locks pigments in place, boosts water resistance and helps products last longer through sweat, humidity or light rubbing. The resulting film is breathable and flexible so makeup stays comfortable and does not crack or flake during wear.
Who Can Use Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer
This lightweight film former is considered suitable for all skin types including oily, dry, combination and sensitive skin because it sits on the surface, does not clog pores and is chemically inert. People with extremely sensitive or compromised skin should still monitor how their skin feels, as any film former can occasionally trap heat or sweat and cause temporary discomfort.
The ingredient is fully synthetic and contains no animal-derived substances so it aligns with vegan and vegetarian lifestyles. Animal testing policies depend on the brand and local regulations rather than the ingredient itself.
Due to its large molecular size the polymer is not expected to penetrate the skin, making it low risk for pregnant or breastfeeding women. This is not medical advice; anyone who is pregnant or nursing should review all personal-care products with a qualified healthcare provider.
The polymer does not increase photosensitivity and can be worn during daytime without raising the risk of sunburn. It is also compatible with most common skincare actives and makeup ingredients.
Potential Side Effects/Adverse Reactions
Individual responses can differ and the following is a list of potential side effects, not what most users should expect. When properly formulated and used as directed, the majority of people will not notice any problems.
- Mild skin irritation such as redness or itching in very sensitive individuals
- Allergic contact dermatitis in rare cases where a person is allergic to one of the polymer’s building blocks or residual solvents
- Eye irritation or stinging if a product containing the polymer accidentally enters the eyes
- Build-up on hair shafts leading to a weighed-down feel if heavily layered without proper cleansing
If any of these reactions occur stop using the product and seek advice from a medical professional.
Comedogenic Rating
Rating: 1 out of 5
This polymer sits on top of the skin in a thin flexible layer and its large molecular size keeps it from slipping into pores. It does not supply extra oil or wax that could feed acne bacteria, and it rinses away with standard cleansers. A score of 1 reflects the very low but not zero chance of clogging when the ingredient is blended with richer emollients or layered heavily without proper cleansing.
Because of the low rating it is generally considered suitable for people who are prone to breakouts.
If you already use several long-wear or film-forming products, make sure to clean the skin well at night to prevent build-up that could trap sweat and oil over time.
Summary
Adipic Acid/Neopentyl Glycol/Trimellitic Anhydride Copolymer is a synthetic film former that creates a light breathable coating over skin, lashes or hair. This film anchors pigments, adds water resistance and extends wear so makeup holds up through sweat or humidity.
It shows up often in long-wear mascaras, eyeliners, liquid lipsticks and transfer-resistant foundations, but you will see it less in everyday moisturizers or cleansers. Its niche popularity comes from the growing demand for makeup that lasts all day without touch-ups.
Safety studies and consumer experience point to a low risk profile with only rare irritation or allergy. Still, everyone’s skin is unique so it is wise to patch test any new product that contains this polymer before using it all over the face.