Emulsifier

PEG-2 Stearate Se

INCI: PEG-2 STEARATE SE

Reviewed by Kate · Last updated 2 Jun 2026

A nonionic emulsifier that stabilises water and oil-based formulations

Best For Skin Types

All

Addresses

Redness, Sensitivity

Effective Concentrations

Up to 5%

Usage Frequency

Daily

What Is PEG-2 Stearate Se?

PEG-2 Stearate SE is a nonionic emulsifier derived from stearic acid and polyethylene glycol. It functions as a surfactant—a molecule with water-loving and oil-loving ends—allowing incompatible ingredients to mix and remain stable within a formula.

In skincare products, this ingredient serves primarily to create smooth, uniform textures by keeping water and oil phases from separating. It is a relatively small polyethylene glycol (PEG) polymer, which affects how it behaves on the skin compared to larger PEG variants.

How It Works

PEG-2 Stearate SE works by positioning itself at the interface between water and oil. One end of the molecule is attracted to water whilst the other is attracted to oil, allowing these normally incompatible substances to mix evenly and stay mixed.

This prevents the typical separation you would see in an unstabilised oil-and-water mixture, ensuring the product maintains a consistent texture and performance throughout its shelf life.

Clinical Evidence & References

Research examining nonionic emulsifiers, including PEG stearates, suggests they are generally well-tolerated on both normal and compromised skin. One study evaluating PEG-2 stearate alongside other emulsifiers in controlled patch testing found minimal irritation potential at typical use concentrations.

However, the evidence base for this specific ingredient remains limited. Most data comes from studies of emulsifier classes rather than PEG-2 Stearate SE in isolation, so individual responses may vary depending on formulation, concentration and skin condition.

How to Use

PEG-2 Stearate SE is a formulation ingredient rather than an active you apply intentionally—it works behind the scenes in creams and lotions. Simply use the product as directed. If you have known sensitivity to emulsifiers or polyethylene glycol polymers, check the ingredient list and consider patch testing before full application.

Safety & Precautions

Generally well-tolerated at typical cosmetic concentrations. Those with PEG sensitivity or emulsifier-reactive skin should be cautious.

Frequently Asked Questions

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