The Science Behind Hyaluronic Acid


Hyaluronic acid seems to be one of the buzziest ingredients in the industry right now. And with the newest product launch from SkinCeuticals having the star ingredient right in the title—we decided to dig a little deeper into the scientific side of this ingredient with Dr. Sherry Ingraham of Advanced Dermatology.

First things first, what is hyaluronic acid?

Hyaluronic acid (or HA for short), is a multi-functioning, naturally occurring molecule found in the human body. HA has the ability to hold nearly 1,000 times its weight in water, helping to plump and moisturize the skin. HA can be found in injectable fillers like Juvéderm or Restylane as well as in topical products, like the newest launch from SkinCeuticals: H.A. Intensifier.

What does HA do when you put it on the skin and when it is in the skin cell; how does it act? How does it actually absorb all that moisture?

Hyaluronic acid does not enter into skin cells, it exists within the epidermis between cells and mainly within the dermis where it exerts its greatest effects. HA binds to one thousand times its weight in water and also helps to regulate water transport and water content in the skin. HA is a critical component of the skin with nearly 50% of the bodies total HA content contained in the skin. The combination of applied HA, hyaluronidase inhibitors and HA stimulators present in the HA Intensifier product have, in studies, resulted in an overall 30% increase in skin HA content as well as an increase in dermal collagen production.

We hear a lot about how HA’s molecular weight means that it can’t penetrate the skin. Some new formulas contain HA in different molecular weights so that they can reach different levels of the skin; can you speak to that?

There is currently no topical HA product on the market that has the ability to penetrate through the epidermis of the skin, due to it’s molecular size. Only hyaluronic acid in the injectable form is able to penetrate the skin. The new SkinCeuticals H.A. Intensifier is unique in that it contains three different forms and sizes of hyaluronic acid: full-size, encapsulated and fragmented. The full-size and encapsulated forms of HA in this product help improve the hydration of the skin by binding to water. Early data suggests that the fragmented (lower molecular weight HA may have a greater benefit on skin texture). However, like all HA’s in topical products, these do not themselves penetrate into the dermis but play a critical role in bringing amplified moisture and water transfer to the skin. When the overall HA content in the skin increases, it creates an ideal environment for collagen to thrive.

Can you talk through how the HA, proxylane, and purple rice extract in the SkinCeuticals H.A. Intensifier formula work together?

Derived from beech trees, proxylane is a naturally-occurring, plant-based sugar derivative that stimulates HA, and therefore collagen, to be created in the skin. This ingredient stimulates the dermis, or the deeper layer of skin, to create more collagen and stimulate the body’s own natural HA production. The inclusion of purple rice extract is one of the most unique qualities in this product. Derived from ancient Chinese rice, this ingredient inhibits the production of hyaluronidase in the skin. Hyaluronidase is the enzyme that breaks down the hyaluronic acid in our skin. The ingredients in the new SkinCeuticals H.A. Intensifier work synergistically to both stimulate hyaluronic acid production as well as prevent the breakdown of naturally occurring hyaluronic acid by inhibiting hyaluronidase.

Why does the HA in our skin degrade so quickly?

HA has a short lifecycle in the skin. 30-50% of it is broken down every 24 hours as part of the normal, natural turnover of the skin. As we age, we make less HA naturally, but levels of the enzyme hyaluronidase (the enzyme that breaks down HA) stay the same. Inflammation and sun damage also cause a decrease in the skins HA levels. As stated, there is naturally a high turnover of HA in the skin and it is replaced, however as we age it is not replaced as quickly nor as completely (while the enzyme that degrades it, hyaluronidase, levels stay the same as we age) and therefore there is ultimately a loss of HA. An overall loss of HA manifests as a loss of functionality of the deeper layers of the skins ability to bind as much water (the important collagen and elastin fibers are not kept as ideally moist and elastic without HA) with a related loss of the youthful plumpness and firmness of the skin as well as a loss of hydration and volumization.

* All information subject to change. Images may contain models. Individual results are not guaranteed and may vary.