What Is Polyquaternium-39?
Polyquaternium-39 is a man-made polymer created by linking together units of acrylamide, dimethyl diallyl ammonium chloride and acrylic acid. The result is a long, flexible chain that carries a positive charge, which helps it cling to hair and skin. It is not harvested from plants or animals but produced entirely in a lab through controlled batch reactions where the raw monomers are mixed, heated and allowed to bond. After the reaction finishes the thick gel-like polymer is purified, adjusted to the right pH, then dried or kept in a water solution ready for use.
The cosmetic industry adopted polyquaterniums in the 1970s as brands looked for conditioning agents that would not build up heavily or rinse away too fast. Polyquaternium-39 quickly gained popularity because its balance of conditioning power and light feel suited modern rinse-off and leave-on products. Today you will spot it in shampoos, hair conditioners, styling gels, leave-in sprays, face masks, moisturizers, primers and even peel-off eye treatments.
Polyquaternium-39’s Cosmetic Benefits/Uses
Formulators choose Polyquaternium-39 for two key reasons that directly improve how a product looks, feels and performs.
- Antistatic – The positive charge in the polymer neutralizes the negative charge that builds up on hair or skin. This reduces static electricity, flyaways and frizz while giving hair a smoother, more controlled appearance.
- Film forming – It creates a thin, flexible layer over the surface it is applied to. On hair this film locks in moisture, boosts softness and adds light hold. On skin it helps retain water, gives a silky after-feel and can tighten peel-off masks so they remove cleanly.
Who Can Use Polyquaternium-39
Thanks to its lightweight film and low likelihood of clogging pores, Polyquaternium-39 is generally suitable for normal, dry, oily and combination skin. Its antistatic action can be helpful for frizzy or flyaway hair types while the gentle film it forms rarely feels heavy on fine strands. Even sensitive skin usually tolerates it well because the polymer sits on the surface rather than penetrating deeply, though anyone with a known sensitivity to quaternary ammonium compounds should proceed with caution.
The ingredient is synthesized entirely in a lab from petro-derived or plant-derived monomers, with no animal by-products involved. This makes it compatible with vegan and vegetarian lifestyles provided the finished brand follows cruelty-free practices.
No data suggest Polyquaternium-39 poses risks to pregnant or breastfeeding women when applied topically in cosmetic concentrations. This is not medical advice, and anyone who is pregnant or nursing should review their skincare routine with their healthcare provider to be safe.
Polyquaternium-39 does not increase photosensitivity, so it will not make skin more prone to sunburn. It is also non volatile, fragrance free and colorless, which helps limit the chances of irritation for fragrance-averse users.
Potential Side Effects/Adverse Reactions
Reactions to topical Polyquaternium-39 can vary from person to person. The points below list potential side effects, though most users will not encounter them when the ingredient is used at standard cosmetic levels.
- Skin irritation – rare cases of redness stinging or itching, especially on already compromised skin
- Contact dermatitis – very uncommon allergic response marked by rash or swelling
- Buildup on hair – excessive use in leave-in products may leave hair feeling dull or weighed down until washed
- Eye irritation – possible if product containing the polymer accidentally gets into the eyes
If any of these effects occur stop using the product and seek medical advice if symptoms persist or worsen.
Comedogenic Rating
Polyquaternium-39 scores a 1 on the comedogenic scale. The polymer sits on the surface as a water-soluble film that readily rinses away, making pore blockage unlikely. A point is deducted only because heavy, repeated layers of any film former could trap existing oil or debris.
With this low score it is considered suitable for people prone to acne or breakouts.
Its quick rinse-off nature in shampoos and wash-off masks, plus the low concentrations used in leave-on products, further limits any clogging potential.
Summary
Polyquaternium-39 delivers two main benefits: it tames static by carrying a positive charge that balances out negatively charged hair and skin, and it forms a light flexible film that locks in moisture provides slip and offers mild hold.
You will find it in everyday shampoos conditioners styling gels and peel-off masks. While not a headline-grabbing ingredient, its consistent performance keeps it quietly popular among formulators.
Studies and long-term consumer use point to a strong safety record with minimal irritation risk. Still, trying any new product on a small patch of skin first is a wise habit.