Polyquaternium-51
Polyquaternium-51 is a synthetic conditioning polymer used in skincare, haircare and makeup products to leave skin and hair feeling silky smooth while helping to lock in moisture.
How it works in skincare
In cosmetics and skincare, Polyquaternium-51 forms a lightweight, breathable film on the surface of skin and hair that binds water and reduces transepidermal water loss. It improves slip and detangling in hair products while giving a soft, velvety after-feel in creams, serums and foundations without any heaviness or tackiness.
Key benefits
- Provides long-lasting hydration
- Improves skin softness and smoothness
- Enhances hair conditioning and detangling
- Creates a protective moisture barrier
- Gives a silky, non-greasy after-feel
- Helps makeup and skincare glide evenly
Best for
dry skin, dehydrated skin, sensitive skin, mature skin
Where it comes from
Polyquaternium-51 is a fully synthetic ingredient produced by polymerising methacryloyloxyethyl phosphorylcholine with other monomers in a laboratory. It is inspired by the structure of natural phospholipids found in cell membranes but does not come directly from any plant, mineral or animal source.
Products with Polyquaternium-51
Not every product on UK Lips lists a full ingredient breakdown — so there may be many more formulas that contain Polyquaternium-51 than we can show here. These are the comparisons where we’ve confirmed it in the listed ingredients.