What Is Polyquaternium-37?
Polyquaternium-37 is a synthetic, water-soluble polymer made from quaternary ammonium compounds. Chemically it is a long chain of positively charged units derived from a methacrylate salt. The “polyquaternium” name simply tells formulators that it is part of a family of conditioning polymers that carry a permanent positive charge.
The ingredient was introduced in the 1980s when cosmetic chemists were searching for alternatives to traditional conditioning agents that could resist rinsing and work well in water-based products. By tweaking the length of the polymer chain and the level of charge, manufacturers created a material that clings lightly to hair and skin without feeling heavy.
Production starts with a quaternary ammonium monomer that is dissolved in water, then exposed to heat or an initiator to kick off a process called free radical polymerization. The individual monomers link together into a stable, high-molecular-weight polymer. After purification and drying the finished powder or bead is ready to be blended into cosmetic formulas.
You will most often see Polyquaternium-37 in hair care such as shampoos, conditioners, mousses, gels and sprays. It also appears in skin care creams, lotions, masks, serums and some makeup primers where a smooth, conditioning feel is desired.
Polyquaternium-37’s Cosmetic Benefits/Uses
This ingredient offers two main functions that improve how a product performs and feels.
- Antistatic – The positive charge neutralizes the negative charge that builds up on hair strands, cutting down on flyaways and frizz so hair stays smoother and easier to style
- Film forming – It lays down a thin, flexible layer on hair or skin that locks in moisture, boosts softness, adds light hold, enhances shine and helps pigments or other active ingredients spread evenly
Who Can Use Polyquaternium-37
Because it is water soluble and lightweight Polyquaternium-37 is generally well tolerated by all skin and hair types, including normal, dry, oily and combination skin. It does not clog pores or leave a heavy residue so even people prone to breakouts usually do fine with it. Those with very sensitive or allergy-prone skin should check ingredient lists for any additional fragrances or preservatives that could be the real irritant rather than the polymer itself.
The material is produced synthetically from petrochemical feedstocks and contains no animal ingredients, making it suitable for vegans and vegetarians. As always cruelty-free status depends on the individual brand’s animal testing policies so look for the appropriate certification if that is important to you.
Current safety data show no specific risks for pregnant or breastfeeding women when Polyquaternium-37 is used topically in rinse-off or leave-on products. This is not medical advice and anyone who is pregnant or nursing should run any skincare product past a qualified healthcare provider just to be sure.
The ingredient does not increase photosensitivity so there is no special need for additional sun protection beyond the usual daily SPF recommendation.
Potential Side Effects/Adverse Reactions
Side effects and reactions to topical Polyquaternium-37 vary from person to person. The points below outline potential issues that could arise, though they are uncommon when the ingredient has been formulated correctly.
- Mild skin redness or irritation
- Allergic contact dermatitis in individuals sensitive to quaternary ammonium compounds
- Eye irritation if product accidentally gets into the eyes
- Product buildup on hair leading to a weighed-down feel if not washed out periodically
If you experience any adverse reaction discontinue use and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0
Polyquaternium-37 molecules are large and water soluble so they sit on the surface and rinse away easily rather than settling into pores and mixing with sebum. Because it forms a breathable film and lacks oily or waxy components it has virtually no tendency to clog follicles, earning it a solid non-comedogenic score.
This makes Polyquaternium-37 suitable for skin that is prone to acne or frequent breakouts.
Occasionally a finished product may still feel heavy if used in high concentrations or combined with richer emollients, so overall formulation matters more than the polymer itself.
Summary
Polyquaternium-37 is a positively charged conditioning polymer prized for its antistatic and film-forming abilities. It smooths hair, cuts frizz, boosts slip and lays down a light moisture-locking layer on skin without leaving buildup. These effects come from its cationic nature, which helps it attract to the negatively charged surface of hair and skin, and its long chain structure, which spreads into a thin flexible film.
You will spot it most often in shampoos, conditioners, gels and a growing number of moisturizers and primers. It is not the trendiest ingredient on social media but formulators like it for its reliability and cost-effectiveness so it appears in many mainstream products.
Current safety reviews rate Polyquaternium-37 as low risk with minimal irritation potential for most users. Still, skin is individual so perform a quick patch test when trying any new product that features this polymer to make sure it agrees with you.