Soya lecithin is a fatty substance that occurs naturally in soybeans. When applied on skin and hair, lecithin softens, conditions and helps to retain moisture.
Lecithin was first isolated by Maurice Gobley in 1850 from egg yolk and named after it (Greek ‘lekithos,’meaning ‘yolk of egg’). It is a vital, structural, cell membrane component of living organisms, and it is produced naturally in the body. Most commercial lecithin now comes from soya bean, from which it was obtained in the 1930s.
Maurice Gobley identified it as the substance that allows oil and water to mix - which makes lecithin unusual in that it's a naturally occurring surfactant. Surfactants are substances used to lower the surface tension of a liquid, which then allows easier spreading of product and helps to emulsify it (blend two ingredients that would otherwise separate, such as water and oil). For this reason, lecithin is a highly valuable ingredient in cosmetics and is also widely used in the food industry to help improve textures.