Polyquaternium-51 ●
TL;DR. This ingredient is primarily a film-forming humectant and conditioning polymer. It helps reduce water loss, improves slip, and leaves a smooth, hydrated feel on skin and hair.
What does Polyquaternium-51 do in a cosmetic formula?
This ingredient is primarily a film-forming humectant and conditioning polymer. It helps reduce water loss, improves slip, and leaves a smooth, hydrated feel on skin and hair.
Is Polyquaternium-51 clean?
From a clean-beauty perspective, it is generally well tolerated on skin, but it has friction because it is a synthetic polymer rather than a simple biodegradable cosmetic material. It is not usually a classic allergen concern, but polymer persistence and restricted natural-standard alignment matter for stricter frameworks.
Is Polyquaternium-51 sustainable?
This material is synthetically produced, typically from petrochemical-derived monomers. Its high molecular weight and polymeric structure mean biodegradability is limited, so environmental persistence is the main sustainability caveat.
Is Polyquaternium-51 COSMOS-approved?
It is not aligned with COSMOS-natural or COSMOS-organic expectations because it is a synthetic polymer outside the usual permitted natural or nature-derived ingredient categories. From a Green Chemistry lens, its performance is efficient at low use levels, but renewable sourcing and ready biodegradability are weak points.
How does Polyquaternium-51 work chemically?
The molecule is a high-molecular-weight methacrylate copolymer with phosphorylcholine-bearing side groups that strongly associate with water and create a thin, substantive film. It is commonly used at low levels, often around 0.1% to 5% active depending on the supplied solution, and it can interact with strongly anionic surfactants or polymers in complex formulas.
Last updated 2026-05-13