Glycerin (a.k.a. glycerol or glycerine), a naturally occurring compound in the body, that is usually sourced from plants for cosmetic formulations, is key for the health and appearance of the skin.
It is a humectant that is able to penetrate deeply into the skin and helps condition it. Glycerin works well with dryer skin types and has been proven to replenish and restore the skin barrier. Some studies have also shown that it could enhance skin penetration of certain ingredients.
Glycerin is part of the skin's Natural Moisturizing Factor (NMF) and it works with other components to maintain adequate skin hydration. It is also involved in the activity of aquaporins in the skin. This involvement is important in order to maintain the skin’s moisture and to help the skin feel smooth and comfortable.