PEG-100 Stearate

PEG / Ethoxylated
Benefits
MoisturizingSoftening
Concerns
Malassezia Feeding

What is PEG-100 Stearate?

PEG-100 Stearate is a synthetic non-ionic surfactant formed by esterifying stearic acid—a saturated fatty acid from plant or animal sources—with polyethylene glycol averaging 100 ethylene oxide units. Commonly found in skincare emulsions like moisturizers, lotions, foundations, and cleansers, it excels as an emulsifier. By reducing surface tension at the oil-water interface, it stabilizes mixtures, preventing separation and ensuring uniform consistency. This enables even spreading and enhances product feel. It also serves as a cleansing aid by forming micelles to lift impurities and solubilizes oils or fragrances into water-based formulas, improving ingredient compatibility and efficacy in daily routines.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1-3 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Surfactant
Lowers surface tension to enable cleansing, emulsifying, and foaming; central to shampoos, body washes, and many emulsions and micellar systems.
Cleansing agent
Removes dirt, oil, and impurities by lowering surface tension and forming micelles, enabling soils to be lifted and rinsed away from skin, hair, or teeth.

Benefits

Stabilizes moisturizers for better hydration retention on skin.

Imparts a softening, smooth sensation during application.

Facilitates gentle cleansing by enabling effective rinse-off.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Users of emulsion-based lotions needing stable hydration.
People susceptible to Malassezia overgrowth conditions.
Those desiring soft, non-greasy textures in daily creams.
Those preferring formulations without ethoxylated compounds.
Individuals incorporating surfactant cleansers for mild impurity removal.
Users with sensitivity to surfactant-based emulsifiers.

Safety Notes

  • Assessed as low to moderate concern by hazard rating systems.
  • Deemed safe in cosmetics by expert review panels when used appropriately.

Frequently Asked Questions about PEG-100 Stearate

What does PEG-100 Stearate do in products?

It emulsifies oil and water phases for stable lotions and cleansers with smooth textures.

Is PEG-100 Stearate irritating?

Evidence indicates low irritation potential in typical formulations.

Can it feed skin fungi?

Noted as a potential Malassezia feeding factor, so caution for prone individuals.