Glyceryl stearate and PEG-100 stearate is a combination of two emulsifying (and emulsion stabilising) ingredients. Glyceryl stearate is a solid and waxy compound. It is made by reacting glycerine (a soap by-product) with stearic acid (a naturally occurring, vegetable fatty acid). PEG-100 stearate is an off-white, solid ester of polyethylene glycol (a binder and a softener) and stearic acid.