What Is Polyamide-7?
Polyamide-7 is a fully synthetic polymer that forms when dilinoleic acid, ethylenediamine and hexamethylenediamine react together, followed by a small chemical “cap” made of propionic acid and acetic acid that helps control the chain length and stability. Dilinoleic acid often comes from plant oils such as soybean or safflower while the two diamines are typically produced from petrochemical feedstocks, giving the ingredient a partly renewable but mostly laboratory origin.
Polyamides first appeared in cosmetics in the early 1990s as chemists searched for light yet durable film formers to replace heavier waxes. Polyamide-7 stood out because it could create a flexible film that resists smudging and water without feeling sticky. Over time manufacturers refined the production process, using step-growth polymerization under controlled heat and vacuum, then filtering and drying the resin into a fine powder or small pellets ready for cosmetic use.
Today Polyamide-7 shows up in a range of beauty products. It helps mascaras, eyeliners and liquid lipsticks stay put, adds long-wear properties to foundations and sunscreens, improves spreadability in moisturizers and barrier creams, and boosts texture in peel-off masks and anti-aging serums.
Polyamide-7’s Cosmetic Benefits/Uses
Below are the main ways Polyamide-7 supports a cosmetic formula
- Binding – acts like a glue that holds pigments, powders and other ingredients together so the product applies evenly and lasts longer
- Film forming – creates a thin flexible layer on skin or lashes that resists water, sweat and transfer giving makeup and skincare a longer wear time
- Skin protecting – the breathable film helps shield skin from external irritants and limits moisture loss which can leave skin feeling smoother and more comfortable
Who Can Use Polyamide-7
Polyamide-7 is considered gentle for most skin types including normal, dry, combination and oily because it sits on the surface rather than sinking deep into pores. Sensitive skin usually tolerates it well since it is non reactive and fragrance free, though any film former can occasionally feel tight on very dry or eczema-prone skin so a richer moisturizer underneath can help.
The ingredient is fully synthetic and does not rely on animal-derived materials making it suitable for vegans and vegetarians. Manufacturers source the plant portion of dilinoleic acid from oil seeds like soybean while the remaining building blocks are produced in a lab.
Current safety data shows no specific risks for people who are pregnant or breastfeeding but this is not medical advice. Anyone expecting or nursing should check with a healthcare professional before starting a new product just to be safe.
Polyamide-7 does not cause photosensitivity so it will not increase the skin’s tendency to burn in the sun. It also plays well with common actives such as vitamin C, niacinamide and chemical or mineral sunscreens because it forms a stable film rather than reacting with them.
Potential Side Effects/Adverse Reactions
Responses to topical Polyamide-7 differ from person to person. The points below outline possible side effects yet most users will not notice any problems when the ingredient is used correctly in a finished product.
- Redness or mild irritation a temporary flush or stinging can show up on very sensitive skin especially if the formula also contains strong solvents or alcohol
- Allergic contact dermatitis rare cases of itching or rash may occur in people allergic to one of the building blocks or trace impurities
- Clogged pores heavy makeup layers that include Polyamide-7 might trap oil and debris in acne-prone skin leading to whiteheads or blackheads
- Eye sensitivity when used in mascaras or eyeliners small flakes can occasionally fall into the eyes causing watering or discomfort
- Dryness or tight feeling the water resistant film can slow natural oil flow leaving very dry skin feeling taut without adequate moisturization beneath
If any discomfort or visible reaction develops discontinue use and seek advice from a pharmacist or healthcare provider for the next steps.
Comedogenic Rating
Rating: 1 out of 5
Polyamide-7 forms a lightweight breathable film that mainly sits on the surface of skin rather than soaking into pores. It has no added oils or waxy fillers, so the chance of it blocking follicles is low, yet any film former can trap existing oil and debris if layers of heavy makeup build up on top. For that reason it earns a mild 1 instead of a perfect zero.
Suitability for acne-prone skin: generally safe for those who break out easily, as long as the rest of the formula is non-comedogenic and makeup is removed thoroughly at the end of the day.
Water-resistant products that rely on Polyamide-7 may require a good cleanser or cleansing oil to lift the film fully, which helps keep pores clear in the long run.
Summary
Polyamide-7 binds pigments, forms a flexible water-resistant film and shields skin from irritants by creating a light barrier. It does this by arranging its long polymer chains across the surface where they lock together, holding color particles in place while still letting skin breathe.
The ingredient is a quiet workhorse rather than a headline star. It shows up often in long-wear makeup, waterproof mascara and some sunscreens, but most shoppers will not notice it listed on the label unless they look closely.
Current research and years of use show Polyamide-7 to be low risk with few reported reactions. As with any new cosmetic, giving the product a quick patch test is a smart way to rule out personal sensitivity before applying it all over.