What it is
Magnesium Stearate is a soft, white metallic soap widely used in pressed and loose powder cosmetics. It enhances powder adhesion to the skin, improves slip, and helps prevent caking and ingredient separation. It is a formulation aid and does not contribute UV protection.
Safety & warnings
Long-established and generally well tolerated in cosmetics and pressed powders. As an inhalable fine powder, loose formats should be handled to avoid inhalation. It is not regarded as notably comedogenic at typical use levels.
Origin & sourcing
Synthetic; produced by reacting a magnesium source with stearic acid, a fatty acid derived from plant or animal fats.
Questions everyone asks
Why is magnesium stearate used in pressed powders?
It helps the powder bind, adhere to skin, and resist caking while contributing a smooth, soft application feel.
Does it protect against the sun?
No. It is a binder and texture agent with no UV-filtering ability.