Lipid: Definition, Properties and Role in Cosmetics

What Is a Lipid?

A lipid is a broad group of naturally occurring substances characterised by their limited solubility in water and generally good solubility in organic solvents. Lipids include fats, oils, waxes, fatty acids, phospholipids, sterols and ceramides.

They are important components of biological structures, including cell membranes and the lipid matrix of the skin's outermost layer.

Lipids in the Skin

Lipids are an important part of the stratum corneum, where they contribute to the organisation of the skin barrier. Key skin lipids include ceramides, cholesterol and free fatty acids.

The composition and organisation of these lipids influence the barrier properties of the skin and its ability to limit water loss.

Lipids in Cosmetic Formulation

Cosmetic formulations use a wide variety of lipid ingredients, including:

• Vegetable oils and butters
• Fatty acids and fatty alcohols
• Waxes
• Esters
• Ceramides
• Phospholipids
• Cholesterol and other sterols

Depending on their chemical structure and properties, lipids can provide emolliency, lubrication, texture, occlusivity and skin conditioning.

Lipids and Skin Conditioning

Lipid ingredients can help improve the feel and appearance of the skin by supporting its surface properties and providing a smoother, softer feel. They are therefore commonly used in creams, lotions, balms, cleansing products and other skincare formulations.