Glycerol Stearate PEG 100 stearate - Emulsifier

Glycerol Stearate & PEG 100 stearate

Synonyms: Primesurf 165

Glyceryl Stearate & PEG-100 Stearate is a paired emulsifier system commonly used in creams and lotions to blend oil and water into a stable, smooth emulsion. It helps create that classic “white cream” texture and gives a nice, non-greasy feel

Composition:

Glyceryl Stearate

• An ester of glycerin and stearic acid (a fatty acid from plant or animal fats).

• Waxy, oil-soluble; contributes to emulsification, skin feel, and a bit of thickening.

PEG-100 Stearate

• A polyethylene glycol (PEG) derivative of stearic acid (PEG chain length ~100).

• Acts as a high-HLB (more water-loving) emulsifier.

What it does in a formula

1. Primary O/W emulsifier

• Helps combine oil phase + water phase into a stable oil-in-water emulsion.

• Without it, oils would separate or form unstable blobs.

2. Texture & skin feel

• Gives creams and lotions that familiar:

  • “creamy but not waxy” texture

  • Smooth, non-draggy application

  • Light to medium emollience without heavy greasiness

3. Stability

• When used with fatty alcohols (e.g. cetyl alcohol, cetearyl alcohol) and sometimes a secondary emulsifier, it helps resist:

  • Separation

  • Coalescence

  • Temperature swings during storage and shipping

Where it’s used

You’ll find Glyceryl Stearate & PEG-100 Stearate in loads of leave-on and rinse-off products, for example:

• Face creams & moisturisers

• Body lotions & butters

• Hand creams

• Sunscreens (especially classic white emulsions)

• Hair conditioners & masks

• Shower creams / cleansing milks

• Serums/emulsions that are creamy rather than gel-based

Typical use levels are something like 2–5% of the blend in the total formula (often ~3–4% in a standard lotion/cream), but you’d follow the supplier’s recommended range.

Why formulators like it

• Reliable, very forgiving emulsifier for O/W creams.

• Works with a wide range of oils (plant oils, esters, silicones).

• Stable across typical cosmetic pH ranges (about pH 4–8).

• Pleasant, familiar sensorial profile that customers recognise.