What it is
Lecithin is a generic term for a group of yellow-brownish fatty substances composed of mixtures of glycerophospholipids, with phosphatidylcholine as a primary component. Because its molecules are amphiphilic, attracting both water and oil, it works as an emulsifier that binds the water and oil phases of a formula together, while also acting as an emollient and skin-conditioning agent. It is frequently used to form liposomes, tiny lipid vesicles that can help carry and distribute other ingredients in a product.
Safety & warnings
Lecithin is widely used across foods, supplements, and cosmetics and is generally well tolerated on skin. Because commercial grades are most often derived from soybean or sunflower, people with specific plant or, for egg-derived grades, egg concerns may wish to check the listed source; routine topical use is considered low risk.
Origin & sourcing
Lecithin is a naturally derived material. Egg yolk was the original source, but the major commercial sources today are plant seeds, especially soybean and increasingly sunflower, with the latter favored where non-GMO sourcing is a concern. Commercially it is obtained by water degumming of extracted seed oils, with composition varying by source.
History
Lecithin was first isolated in 1845 from egg yolk by the French chemist Theodore Gobley, who named it in 1850 after the Ancient Greek word lekithos, meaning egg yolk. Gobley went on to establish the chemical formula of phosphatidylcholine by 1874. Commercial production later expanded to plant sources such as soybean and sunflower.
Questions everyone asks
Where does cosmetic lecithin come from?
Most commercial lecithin is extracted from soybean or sunflower seed oils, though egg yolk was the original source.
What does lecithin do in a sunscreen?
It emulsifies the water and oil phases so the formula stays blended, conditions the skin, and can form liposomes that help distribute other ingredients.
Is lecithin safe for sensitive skin?
It is generally well tolerated in topical products. If you have a soy or egg sensitivity, check the source listed on the label.