A Guide to Emulsifiers in Skincare

Practical advice to help you understand the role of emulsifiers in your products.

Introduction: Why Emulsifiers Matter

Emulsifiers are unsung heroes in many skincare products — especially moisturisers and cleansers — because they help blend oil and water into a smooth, usable texture. Without emulsifiers, many products would separate, feel gritty, or apply unevenly. But not all emulsifiers are made equal — and understanding which ones support the skin barrier (and which might harm it) is key to making informed skincare choices.

What Are Emulsifiers?

Emulsifiers are ingredients that stabilise mixtures of water and oil, allowing them to blend smoothly into lotions, creams, and milks. They typically contain two molecular “ends” — one that binds to water, and another to oil. By keeping water and oil dispersed evenly, they give skincare its texture and help it spread across the skin.

Where You’ll Find Them

- Moisturisers: Most creams and lotions use emulsifiers to maintain a stable emulsion.

- Cleansers: Especially cream or milk cleansers, and some micellar waters.

- Sunscreens: Many broad-spectrum SPFs include emulsifiers to keep formulations stable.

- Makeup products: Primers, foundations, and tinted moisturisers also rely on emulsifiers.

Types of Emulsifiers: Not All Are Equal

Emulsifiers are broadly categorised by their ionic charge — and this affects their behaviour on the skin:

- Anionic Emulsifiers: These carry a negative charge and include ingredients like Sodium Lauryl Sulfate (SLS). They’re powerful cleaners, but can disrupt the skin barrier by interacting with natural lipids.

⛔ *More likely to contribute to “washout effect.”*

- Cationic Emulsifiers: Positively charged, they’re more often used in haircare. Can be irritating for skin in high concentrations.

- Non-Ionic Emulsifiers: These carry no charge and are typically gentler on skin. Examples include cetearyl alcohol, glyceryl stearate, and polyglyceryl-3 methylglucose distearate.

✅ *Often preferred in barrier-supportive skincare.*

The Washout Effect: What It Is and Why It Matters

Some emulsifiers — especially stronger anionic ones — can gradually weaken the skin’s barrier by emulsifying its own protective lipids. This leads to the so-called “washout effect,” where repeated exposure pulls natural oils and hydration out of the skin, increasing dryness and sensitivity over time.

What the Label Might Not Tell You

- Products rarely declare whether their emulsifiers are gentle or harsh.

- Some emulsifiers are hidden under complex names (e.g. PEG-100 Stearate).

- “Natural” doesn’t always mean “gentle” — some plant-based emulsifiers are still disruptive.

- Just because a product is labelled “for sensitive skin” doesn’t mean its emulsifier is safe for barrier-compromised skin.

🔴Red Flag Emulsifiers

These are best avoided if your skin is sensitive, reactive, or currently compromised.

• Sodium lauryl sulfate (SLS): A harsh cleansing agent that can strip the skin’s natural lipids.

• Sodium cetearyl sulfate: Not to be confused with cetearyl alcohol — this sulfate can be irritating and drying.

• Ammonium lauryl sulfate: Similar to SLS; known to weaken the barrier and cause sensitivity.

• PEG-based emulsifiers (e.g. PEG-100 stearate):

  • PEG stands for polyethylene glycol.

  • These are synthetic compounds used to blend water and oil.

  • Some can increase product penetration — not ideal for damaged or sensitive skin.

  • They may also carry trace impurities from processing, although many are purified.

  • If your skin is dry, red, or irritated, it’s safest to avoid PEG ingredients where possible.

🟢 Barrier-Friendly Emulsifiers

These emulsifiers are generally well-tolerated and less likely to interfere with the skin’s natural defences.

• Cetearyl alcohol: A fatty alcohol — not drying — that helps soften the skin and stabilise creams.

• Glyceryl stearate: Derived from glycerin and stearic acid, it supports hydration and has a low irritation risk.

• Polyglyceryl-3 methylglucose distearate: A plant-derived emulsifier often used in barrier-supportive products; gentle and non-stripping.

• Lecithin: Naturally found in the body, it helps protect the skin barrier and improve product absorption.

• Caprylyl/capryl glucoside: A sugar-based emulsifier that’s mild, biodegradable, and often found in sensitive-skin formulas.

💡 These are especially useful in moisturisers or cleansers designed for dry, sensitive, or recovering skin.
They help keep water and oil working together without pushing active ingredients too deeply or disturbing the barrier.

Final Thoughts

Emulsifiers are essential in the vast majority of skincare products — particularly those outside of the specialist realm of corneotherapy. However emulsifiers need to be used wisely. In barrier-supportive skincare, the aim is not to eliminate emulsifiers altogether, but to choose the *right kind* for your skin’s needs. For many people, especially those with sensitivity, dryness, or conditions like rosacea, gentle non-ionic emulsifiers are best.

By learning how emulsifiers work — and which ones are worth avoiding — you empower yourself to make better decisions. Because when your skin barrier is strong, everything else works better.