Emulsifier

Potassium Stearate

INCI: POTASSIUM STEARATE

Reviewed by Kate · Last updated 14 Aug 2026

A potassium salt surfactant that cleanses and stabilises emulsions

Best For Skin Types

All

Addresses

Oil control

Usage Frequency

Daily

What Is Potassium Stearate?

Potassium stearate is a potassium salt derived from stearic acid, a naturally occurring fatty acid. It functions as a surfactant and emulsifier in skincare formulations, meaning it helps oil and water mix together and can assist in removing oil-based impurities from the skin.

It appears in a small proportion of skincare products, typically in cleansers and emulsified formulations where its role is primarily structural rather than targeted for specific skin benefits.

How It Works

Potassium stearate molecules have a water-loving head and an oil-loving tail. This dual nature allows them to surround oil-based particles on the skin and suspend them in water, enabling them to be rinsed away. In formulations, they also sit at the boundary between oil and water phases, preventing separation and maintaining product texture.

How to Use

Potassium stearate is typically encountered in cleansing products rather than serums or treatment formulations. Use products containing it as directed on the label; in cleansers, massage gently onto damp skin and rinse thoroughly with water.

Safety & Precautions

Potassium stearate is well-tolerated by most skin types. Those with sensitive skin or known sensitivities to soap-based ingredients may wish to patch test first.

Frequently Asked Questions

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