What it is
Glyceryl stearate is a monoglyceride formed by combining glycerin (glycerol) with stearic acid, a fatty acid. It functions as an emulsifier, enabling oil-based and water-based ingredients to blend into a stable mixture, and as an emollient that conditions skin and adds body and a smooth feel to creams. It appears as a waxy, flaky solid and is one of the most common workhorse emulsifiers in lotions and creams.
Safety & warnings
Glyceryl stearate is very well tolerated on skin and is also used as a food additive, with a long record of safe use. Because it is a simple ester of glycerin and a common fatty acid, it rarely causes irritation or sensitization, which is why it is found across a wide range of leave-on and rinse-off products for most skin types.
Origin & sourcing
Glyceryl stearate can be produced from most vegetable oils, by a process related to soap-making that joins glycerin with stearic acid. Industrially, the related glycerol monostearate is typically made by glycerolysis, reacting triglycerides from vegetable or animal fats with glycerol. It is readily biodegradable, and the body itself forms this type of monoglyceride naturally when pancreatic lipase digests dietary fat.
Questions everyone asks
What does glyceryl stearate do in sunscreen?
It is mainly an emulsifier and emollient, holding the oil and water phases together so the cream stays uniform while conditioning the skin and adding body.
Is glyceryl stearate natural?
It can be made from most vegetable oils by joining glycerin with stearic acid, and the body even forms this kind of monoglyceride naturally when digesting fat.
Is glyceryl stearate safe for sensitive skin?
It is generally very well tolerated and rarely irritating, which is why it is used widely in products for most skin types, including sensitive skin.