Ingredient dictionary

Polyquaternium-37

Polyquaternium-37 is a synthetic polymer with positive charges that cling to hair. Its main job is to condition, smooth and reduce static. It is on the label of 16 products in our library. Checked against our library November 6, 2026.

What Polyquaternium-37 does

Helps tame frizz and flyaways
Adds slip for easier detangling
Helps reduce static in dry hair

Polyquaternium-37 is made by chemically linking smaller building blocks into a long chain. Some of those blocks carry quaternary ammonium groups, which hold a positive charge. The name follows the cosmetic naming system: the prefix marks a polymer with these groups, and the number tells it apart from the others.

Hair is slightly negative when dry or damaged, so the positive charge helps the polymer cling to it. The thin film it leaves smooths the hair surface, reduces static and helps hair feel softer and easier to comb. In conditioners it adds slip, and in hair color formulas it helps condition hair during the process.

Good for

Suits most hair types, especially dry, frizzy or color-treated hair that needs softness and manageable styling.

Frequently asked questions

What does Polyquaternium-37 do in hair?

It acts as a conditioning polymer. Its positive charge grabs onto hair, leaving a light film that smooths the surface, reduces static and makes strands easier to comb. It is common in conditioners and hair color formulas.

Can Polyquaternium-37 cause buildup?

Like many conditioning polymers, it can leave residue if used heavily or often. Hair may feel coated or look dull over time. A clarifying shampoo now and then can help clear it, and most people using it normally notice no problem.