When it comes to cosmetics, lecithins from a soy lecithin basis are used primarily as emulsifiers but also have moisturizing properties and serve as moisturizers for cosmetic pigments. They also stabilize the barrier layer of the skin and restructure the skin's natural properties. Soy lecithins are ideally suited for non-greasy, mattifying emulsions with a high protective nature and water repellency, as desired for example, in the manufacture of hand creams. They are also often used as a skin softener in foot creams to make rough skin luxuriously soft.
see: Heike Käfer 2010 "Natural Cosmetic Raw Materials", Linz, Freya Verlag, 3rd Edition 2012