Glyceryl Stearate Citrate

Overview

Glyceryl stearate citrate is a natural-positioned emulsifier made by combining glycerin with stearic acid (a fatty acid from plant or animal fats) and citric acid. The result is a waxy off-white solid that melts cleanly into the oil phase of a formula and produces stable oil-in-water emulsions.

It is one of the small group of “natural” emulsifiers that comply with Ecocert, COSMOS, and other clean-beauty certifications. The molecule has a hydrophilic-lipophilic balance (HLB) around 9-10, which suits it for medium-weight lotions and creams.

Unlike older emulsifying waxes (like emulsifying wax NF), glyceryl stearate citrate produces a lighter, less waxy finish on the skin. Lotions feel more cosmetically elegant — closer to a department-store finished cream than a homemade lotion.

Shelf life as a raw material is 2-3 years stored cool and dark.

It is a popular choice for natural-positioned face creams, lotions, and body milks where the formulator wants a clean-feel emulsion without resorting to synthetic emulsifiers.

What it does in a formula

The molecule sits at the oil-water interface in an emulsion. The glyceryl stearate end is lipid-loving and anchors in the oil phase; the citrate end is water-loving and reaches into the water phase. This positioning at the interface stabilizes the oil droplets and prevents them from coalescing — that is, it keeps the emulsion smooth and stable.

The citrate component also gives a slight pH-lowering effect, which is useful in keeping the formula slightly acidic and skin-compatible.

In a formula glyceryl stearate citrate produces a light to medium lotion with a soft, non-greasy finish. It pairs well with co-emulsifiers like cetyl alcohol (for thickening) and with most actives.

How to use

Add to the oil phase. Heat-and-hold both phases at 70-75 C, combine, and emulsify with a stick blender or homogenizer. Hold at 70 C for 15-20 minutes for stability.

Usage rates by product type:

• Light face lotions: 3-5%
• Body lotions: 3-5%
• Day creams: 3-6%
• Eye creams: 3-5%
• Cleansing milks: 2-4%
• Hair conditioners (rinse-off): 2-4%
• Light hand creams: 3-5%

Pair with co-emulsifiers (cetyl alcohol, cetearyl alcohol, glyceryl stearate SE) at 1-3% for thicker creams.

Best for / Worst for

Best for: light to medium natural-positioned face and body lotions, cleansing milks, hair conditioners, formulas marketed on Ecocert/COSMOS certification, lotions for sensitive skin.

Worst for: thick body butters (use heavier emulsifiers), water-in-oil emulsions (this is an oil-in-water emulsifier), very oil-heavy formulas (above 30% oil phase needs a stronger emulsifier).

Common pitfalls

Wrong phase temperatures. Both oil and water phases need to be at 70-75 C when combined. If the temperatures are mismatched the emulsion may not form properly or may separate later.

Under-emulsifying. A quick stir is not enough. Use a stick blender or homogenizer for 1-2 minutes during initial combination and a second 30-second blend at 50 C during cool-down for stability.

Too low percentage. Below 2% the emulsion may be unstable. Start at 3-4% and adjust.

Substitutes

• Olivem 1000 — close on natural positioning, similar light finish.
• Montanov 68 — natural emulsifier, similar use.
• Emulsifying wax NF — synthetic, easier to work with, less natural positioning.
• Polawax NF — similar to E-wax, more reliable for beginners.