Hyaluronic acid (also called Hyaluronan) is a component of connective tissue whose function is to cushion and lubricate. In the human body, it is found in greatest concentrations in the joints for lubrication, the vitreous humor (fluid) of the eye, and most abundantly in the skin. As we age, the body produces less and less Hyaluronic acid. This lack of Hyaluronic acid can cause the skin to become dry and wrinkly. Often referred to as HA for short, the molecule is a naturally-occurring substances in the skin — a group of carbohydrates that work to help maintain its elasticity. It's what's known as a "humectant," meaning it works like a sponge to help skin retain water and leave it plump and dewy.
Hyaluronic acid has been nicknamed by the press as the "key to the fountain of youth"; because it has been noted that at least some people who ingest a lot of it in their diets tend to live to ripe old ages. Hyaluronic acid is capable of holding more water than any other substance and it creates an ideal environment for the generation of new skin cells, keeping skin smooth and elastic. Hyaluronic acid has excellent water-binding properties and therefore is a natural moisturizer. Hyaluronic acid holds water so tightly it appears to be a gel, which it is not. It is a true liquid and maintains all the properties of a liquid. Hyaluronic acid that is applied to the skin will hold water in much the same way that it holds water in the intercellular matrix of the dermal connective tissue. This water holding ability makes hyaluronic acid an ideal hydrating base and an excellent vehicle for the delivery of other agents to the skin. Because hyaluronic acid can hold up to a thousand times its weight in water, when applied after microdermabrasion, it is very soothing as well as hydrating.
Especially good for those with dry skin, hyaluronic acid draws moisture into skin and prevents it from leaving. It is also been found that hyaluronic acid appears to have a positive effect on wound healing as well as soothing inflammatory and collagen remodeling.
According to the experts, the hero ingredient needs to be applied to damp skin in order to work. In fact, applying it to a dry face can have the opposite effect of what is intended, and actually leave skin more dehydrated. "Hyaluronic acid is a moisture magnet," says Allies of Skin founder Nicolas Travis. "But if your skin is dry, it pulls any residual moisture from the deeper layers of skin to hydrate the surface. In that case, you need to apply it to moist skin — which is why you should mist first and then apply a hyaluronic acid treatment afterwards. Once hyaluronic acid comes into contact with water, it knows what it's doing and your skin will end up supremely hydrated and plumped."
It makes sense, when you think about it: Hyaluronic acid doesn't contain any water itself, so the more moisture you combine it with, the better it performs. Think of your regimen as a hydration "sandwich" — spritz your face with water or a facial mist, apply the hyaluronic acid treatment, then spritz again.