Soy sterol is a polyethylene glycol (PEG) derivative of soybean oil sterols. Soy sterol helps to form emulsions by reducing the surface tension of the substances to be emulsified.
Soy Sterol Uses
PEG-5 and PEG-10 soy sterol are used in a variety of cosmetic formulations to enhance the appearance of dry or damaged skin by reducing flaking and restoring suppleness. PEG-40 soy sterol also helps other ingredients to dissolve in a solvent in which they would not normally dissolve and cleans the skin and hair by helping water to mix with oil and dirt so that they can be rinsed away.