Polyglyceryl-4 Isostearate is a plant-based emulsifier used in cosmetics and skin care products to stabilize formulas. One of its main components, Isostearic Acid, is a mild fatty acid also seen in many cleansers and cosmetic powders. Little information is available regarding Polyglyceryl-4 Isostearate, although it does appear in many products as a primary emulsifying agent (SusanBrownsBaby.com, a cosmetics company, and The National Institutes of Health).
Safety Measures/Side Effects:
Polyglyceryl-4 Isostearate is considered a low hazard ingredient by the Cosmetic Database, noting only data gaps as a concern. No studies were found that noted any adverse reactions or side effects upon using this ingredient in cosmetic or skin care formulas.