Glycerol monostearate or monostearin, is a monoglyceride commonly used as an emulsifier in foods. Chemically it is the monoglycerol ester of stearic acid. Glyceryl stearate is a food additive used as a thickening, emulsifying, anticaking, and preservative agent, an emulsifying agent for oils, waxes, and solvents a protective coating for hygroscopic powders, a solidifier and control release agent in pharmaceuticals, and a resin lubricant. Glyceryl monostearate is also used in cosmetics and hair-care products. It is generally a white, odorless, and sweet-tasting flaky powder that is hygroscopic.

Glycerol monostearate, also known as monostearin or glyceryl stearate, is a monoglyceride formed by the esterification of glycerol with stearic acid and is widely used across the food, pharmaceutical, and cosmetic industries due to its versatile functional properties. Because it contains both hydrophilic (water-attracting) and lipophilic (oil-attracting) components, it acts primarily as an emulsifier, helping oil and water mix in products such as baked goods, ice cream, margarine, and sauces, while also functioning as a thickening agent, stabilizer, anticaking agent, and preservative aid to improve texture and shelf life. In pharmaceuticals, it serves as a solidifier, lubricant, protective coating for hygroscopic powders, and controlled-release agent in tablets and capsules. In cosmetics and hair-care products, it enhances texture, improves spreadability, stabilizes formulations, and provides a smooth, moisturizing feel to the skin and hair. It typically appears as a white, odorless, slightly sweet-tasting, flaky or waxy powder that is hygroscopic in nature.