li·po·somes (LY-poh-zohms) n. tiny balls of lipids (fats) derived from a mixture of water and phospholipids that deliver moisture to the skin and are used in moisturizers. Because of their small molecular size, they are able to penetrate the cell wall particularly well. They are also able to absorb water-soluble nutrients and vitamins.
Liposomes are not active themselves, but are believed to function in creams as carriers of various encapsulated active substances that otherwise could not penetrate the skin’s fatty layers. Once applied, stored nutrients and vitamins are theoretically released into the skin or hair.
However, there’s some argument that liposomes are ineffective because scientists speculate that they break down when they hit the skin’s surface, before they can aid in having active ingredients penetrate the skin. Skin is intended to act as a protective barrier – designed by evolution to keep us safe from the elements of the world that might damage us. Because of this, it’s more difficult than beauty advertisers would like you to think for their ingredients to penetrate and rejuvenate this protective barrier.