---
title: "Emulsifier — Glossary | School of Dermatology"
url: https://schoolofdermatology.com/glossary/emulsifier
description: "Learn what emulsifiers are, how they combine oil and water in skincare products, and why they matter for product texture and stability."
lang: en
---

Glossary

# Emulsifier

ee-MUL-sih-fy-ur

## Definition

An emulsifier is an ingredient that allows two normally immiscible substances — typically oil and water — to mix together into a stable, uniform formulation called an emulsion. Most skincare products like lotions, creams, and serums are emulsions. Without emulsifiers, oil and water components would separate. Common emulsifiers include cetearyl alcohol combined with polysorbate 60, lecithin, ceteareth-20, and glyceryl stearate. Emulsifiers have both hydrophilic (water-attracting) and lipophilic (oil-attracting) parts, allowing them to bridge the gap between oil and water phases. In skincare formulation, the choice of emulsifier affects product texture, stability, absorption, and feel on the skin. Some emulsifiers can be irritating to sensitive skin, particularly those based on certain sulfates or polyethylene glycol (PEG) compounds.

## Related Terms

Moisturizer: https://schoolofdermatology.com/glossary/moisturizer
Barrier Function: https://schoolofdermatology.com/glossary/barrier-function

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