A synthetic or soy-derived (PaulaŠ—Ès Choice Skincare uses the latter) ingredient used in cosmetics as a cleansing agent and emulsifier. As a class of ingredients, soy-based phytosterols are generally recognized as safe for use in cosmetic products.
Reference for this information:
International Journal of Toxicology, Volume 23, 2004 Supplement 2, pages 23-47