Glycosaminoglycans: What They Are and Where Hyaluronic Acid Fits
Quick facts
- Definition
- Long chains of repeating sugars that hold a lot of water in the extracellular matrix.
- Examples
- Hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparan sulfate and keratan sulfate.
- Role in the skin
- Hydration, volume and lubrication of the matrix that surrounds collagen and elastin.
- Key point
- Hyaluronic acid is the non-sulfated GAG with no core protein, which makes it the basis of fillers.
Glycosaminoglycans, or GAGs, are long chains made of repeating sugars. They sit in the extracellular matrix, the space between the cells of the dermis, where they attract and hold a large amount of water. The result is a hydrated gel that gives the skin volume and cushioning.
What are the main GAGs?
| GAG | Feature |
|---|---|
| Hyaluronic acid | Non-sulfated, free, very long chain |
| Chondroitin sulfate | Sulfated, usually bound to proteins |
| Dermatan sulfate | Sulfated, abundant in the dermis |
| Heparan sulfate | Sulfated, bound to the cell surface |
| Keratan sulfate | Sulfated, bound to proteins |
Sulfated GAGs are anchored to proteins, forming proteoglycans. Hyaluronic acid is the one that circulates free, with no core protein, which is why it was chosen as the basis of fillers and hydration products.
Where does this touch HOF?
GAGs are produced by fibroblasts, the same cells that make collagen and elastin. With age, synthesis drops and the skin holds less water, which is part of facial aging. HA's ability to attract water is covered in hydrophilicity of hyaluronic acid.
Frequently asked questions
What are GAGs in the skin?
They are long-chain sugar molecules that attract and hold water in the matrix of the dermis. They provide hydration, volume and support for collagen and elastin fibers.