PEG-90 Glyceryl Isostearate

PEG-90 Glyceryl Isostearate is a synthetic surfactant—a cleansing molecule made by combining polyethylene glycol (PEG) with glyceryl isostearate, a fatty acid derivative. It belongs to the class of emulsifiers and solubilisers commonly used in skincare and cosmetics.In formulations, this ingredient functions as a cleanser and helps dissolve oils, makeup and impurities from the skin's surface. It is used in relatively low concentrations and is found in roughly 0.1% of skincare products, typically in cleansing formulas rather than leave-on treatments.

PEG-90 Glyceryl Isostearate works by reducing the surface tension of water and oils, allowing them to mix together. This process, called emulsification, enables the ingredient to surround oily substances and suspend them so they can be rinsed away with water.Because it is a synthetic, mild surfactant, it is designed to perform this cleansing action without the irritancy sometimes associated with harsher detergents. It is typically used in rinse-off products where it does not remain on the skin long-term.

Use this ingredient as directed in your cleanser—typically applied to damp skin, massaged gently, then rinsed thoroughly with water. Because it appears in rinse-off products, no special application technique is required beyond standard cleansing practice. If you have sensitive skin, patch test first and discontinue if irritation occurs.

PEG-90 Glyceryl Isostearate is generally well-tolerated and considered safe for cosmetic use. Some individuals with very sensitive skin or fungal acne concerns may prefer to avoid it, though evidence linking it specifically to fungal acne is limited.