Magnesium stearate is a fine white powder that consists of magnesium and stearic acid, a naturally occurring fatty acid commonly sourced from vegetable oils. It serves as a widely used pharmaceutical and cosmetic additive because of its properties as a lubricant and anti-caking agent. In cosmetics and skincare products, magnesium stearate is often used to improve product texture, prevent clumping and improve the overall stability of formulas like pressed powders, creams, lotions and even sunscreen.