What is Hyaluronic Acid?
Hyaluronic acid, also known as hyaluronan and HA for short, is a substance that retains moisture. Also known as a humectant, HA has the impressive capability of binding to water. In fact, some say that a single HA molecule can bind to more than one thousand times its weight in water!
Hyaluronic acid is a naturally-occurring substance in the human body, composed of polysaccharides (sugar). It serves to cushion and lubricate and can be found in the brain, eyes, blood vessels, organs, and joints. However, the skin contains the most HA. Each skin cell is surrounded by hyaluronic acid.
Because of its ability to attract so much moisture, HA is a crucial component in the skin – where hydration is vital. After all, we know what happens to the skin when it lacks moisture: it becomes dry, flakey, and rough. In addition, the skin no longer can shield itself from environmental factors. This allows harmful bacteria to propagate, which dramatically increases the risk of inflammation and infection.
With good levels of HA, the skin is stronger, healthier, and supple. Its barrier functions properly, keeping harmful bacteria out. Visually, the skin looks plump and youthful.
Aging and Hyaluronic Acid
Unfortunately, aging causes hyaluronic acid levels in the skin to decrease gradually. This tends to occur at a faster pace when you hit your 40s. Combined with depleting collagen and elastin levels, the skin becomes drier, thinner, and more fragile.
That’s why so many anti-aging treatments operate by restoring HA levels in the skin. As a therapeutic ingredient, it is well received by all types of skin (very rarely does it cause an adverse reaction, and if a product does cause one, it’s typically because of another ingredient present).
HA treatments include topical skincare products and dermal fillers.
For topical skincare products, HA comes in three types:
- Hydrolyzed hyaluronic acid is when the HA molecules have been broken down into a smaller size to better penetrate the skin surface.
- Sodium hyaluronate has an even smaller molecular weight so that it can go deeper into the skin.
- Sodium acetylated hyaluronate, also known as super hyaluronic acid, has a small molecular weight like sodium hyaluronate but features acetyl groups that “anchor” HA molecules to the skin. As a result, this ingredient provides longer-lasting hydration.
If you want better penetration of topical skincare products and have drier skin, consider choosing those that contain sodium hyaluronate or sodium acetylated hyaluronate. Hyaluronic acid with a higher molecular weight will sit more on the skin’s surface and only work at that superficial level.
Dermal fillers (also known as injectable fillers) are injectable products that add volume to the skin in order to reshape contours, smooth creases as well as plump up areas that are disproportionate. The active ingredient in many dermal fillers on the market today is hyaluronic acid. Because they are injected right into the skin at a shallow depth, dermal fillers tend to be more effective in replenishing HA levels than topical skincare products. More HA can be predictably added as well, and the improvement can be seen instantly. However, patients are advised to wait until minor bruising and swelling subside before assessing their results.
HA molecules in dermal fillers come in various molecular weights, measured in a unit known as kDa. Each product features HA in a unique molecular weight, typically ranging on average from 500 to 6,000kDa. This, along with the product’s texture (viscosity), determines where it should be injected and for what purpose. Areas that are frequently treated with fillers include the forehead, around the eyes, temples, cheeks, jawline, lip, nose, earlobes, and hands. Manufacturers label the molecular weight of their products.