Hyaluronic acid is a substance in your skin that helps to retain moisture, stimulate tissue repair, and contribute to mechanical resilience and suppleness of the skin. But as you get older, you do not have as much of this substance in your skin cells anymore.
This is mainly because the activity of an enzyme called hyaluronidase increases, which is what ultimately breaks down HA in your skin.
A quality hyaluronic acid firming serum will contain ingredients that address this issue by stopping the activity of this enzyme so you can have more HA in your skin as you age. You can also buy the best firming serums, available at online stores.
Don't even bother with products that actually contain HA as an ingredient because HA molecules are too large to penetrate through the skin.
Loss of collagen and elastin production
Collagen and elastin are the structural proteins in your skin that determine how firm and elastin it stays. These are actually the building blocks of your skin, and HA molecules are the fillers that take up space between these proteins.
Together, they form your skin matrix. Just like with HA, the amounts of collagen and elastin in your skin decrease as you get older.
The best hyaluronic acid firming serum will contain ingredients that stimulate the natural production of these proteins in order to keep your skin firm and tight as you age.
Again, do not bother with products that actually contain collagen and elastin as ingredients because just like HA, these proteins are too large to penetrate through your skin.