Glycosaminoglycans, also referred to as GAGs, are long, unbranched polysaccharides that are found in the extracellular matrix of connective tissues throughout the body, including the skin. They are known for their ability to bind and hold onto water molecules, which contributes to the skin’s hydration and plumpness.

In skincare, glycosaminoglycans are often used as humectants, which means they help to attract and retain moisture from the air. They can also help to improve the skin’s barrier function and protect it from environmental damage. Some common glycosaminoglycans used in skincare include hyaluronic acid, chondroitin sulfate, and dermatan sulfate.