Emulsifying and conditioning
Used in haircare products, stearic acid coats the hair shaft, providing condition and protection without making it dull or heavy. It is also used as an emulsifier in lotions and makeup.
Cosmetic creams and lotions are often composed of water and oil-based ingredients, which are held together by substances called emulsifiers. Without emulsifiers, the formula would separate, causing oil droplets to float on top of the water. Stearic acid is an emulsifier by itself, but can also be used with triethanolamine. When mixed, the two compounds react and become a paste called ‘triethanolamine stearate’ that helps to create a loose emulsion which is easily absorbed by the skin.
Usually, Lush use a vegetable-based stearic acid, derived from palm oil. Because completely palm-free stearic acid is so difficult to find, we’ve worked with suppliers to produce a new version from other vegetable oils. In 2017, one of these attempts, derived from olive oil, has finally succeeded and has been introduced in a few products.
Why a few and not all our products then? Because it's not that simple. One material does not necessarily replace the other. As they are not derived from the same oil, they do not behave in the same way and switching them affects the appearance, shelf life and effectiveness of products. This is why we are also working on formulas to try and remove stearic acid completely when possible, without affecting the quality of the product.