Hyaluronic Acid is another hero ingredient in skin care products, and we are now seeing it everywhere. It occurs naturally in our skin, where it provides protection to cell structures and serves as a water reservoir.
Hyaluronic Acid acts as a major structural component of skin, along with collagen and elastin, and plays an important role in the skin’s lipid layer. It is one of our skin’s natural moisturising factors. These natural moisturising factors are a collection of water-soluble compounds found in corneocytes, which are individual skin cells found in the outermost layer of the epidermis.
Our bodies synthesise Hyaluronic Acid. This is done by our fibroblasts, fibrocytes and roving stem repair cells. However, as we age, this process slows down. Our skin not only starts to lose Hyaluronic Acid, but it becomes less efficient in creating more of this magical stuff. As a result, our skin no longer has the ability to hold onto water in the cells like it did before and to protect itself from external stressors.
Hyaluronic Acid in the skin maintains the intercellular reservoir, thereby keeping our skin looking plump, smooth and youthful.
Another marvel of natural Hyaluronic Acid in the skin is that it decreases the inflammatory response. When the skin is wounded, the body will produce more Hyaluronic Acid, and this promotes healing and regeneration.
In skin care, Hyaluronic Acid as an ingredient has captured everyone’s attention because of its remarkable ability to bind water and hydrate skin. It holds up to a 1000 times its weight in water, thereby quenching dry skin and making skin appear smoother and those pesky lines less visible. It is also used in skin care in the form of Sodium Hyaluronate and functions in the same way as Hyaluronic Acid. This makes it a wonderful humectant for the skin, with benefits for all skin types.
That dewy, hydrated look is much prized in skin care and this has meant that Hyaluronic Acid has been manipulated by the skin care industry at the expense of your skin.
Hyaluronic Acid, as a skin care ingredient, has a high molecular weight, which means it cannot efficiently penetrate the barrier of the epidermis. Instead, it sits on the surface of the skin to help lock in moisture and keep nasties out. As a result, skin care companies have sought competitive by creating low to ultra low molecular weight Hyaluronic Acid formulas in their skin care ranges, and this has created its own set of problems and worrying consequences.
Hyaluronic Acid with an ultra low molecular weight, such as Hydrolysed Hyaluronic Acid, has been found to have pro-inflammatory effects on the skin, and so products with this ingredient may be doing more harm than good. Anything that sets off an inflammatory cascade in the skin is going to be pro-ageing rather than anti-ageing. Current research tells us that the smallest molecular size of Hyaluronic Acid is not the best for skin, as some skin care brands would have us believe. Multiple studies have shown that ultra low molecular weight Hyaluronic Acid activates the inflammatory cytokine TNF-alpha in the skin.
It is not easy to determine the ideal weight for Hyaluronic Acid, especially as the research in this area has not clearly defined this yet.
Skin care formulations typically use Hyaluronic Acid that has a high molecular weight, but this does not achieve penetration. Research into Hyaluronic Acid at ultra low and low molecular weights has shown it penetrates more deeply and is more active, thereby bringing about significant improvement in skin hydration and wrinkle depth. But one major study also showed higher levels of the inflammatory cytokine TNF-alpha when Hyaluronic Acid is applied in sizes 20kDa, 50kDa and 130kDa. Other studies have confirmed the pro-inflammatory effects of ultra-low Hyaluronic Acid, and possibly also low molecular weight Hyaluronic Acid. In one, it was found that an inflammatory marker in the skin began to rise and was above baseline when Hyaluronic Acid at 320kDa was applied.
Keep in mind that most of the research on the use of Hyaluronic Acid on skin has been done on wounds, whereas Hyaluronic Acid in skin care is being applied to intact skin, or at least should be!
So what does all this mean? The takeout is that ultra low molecular weight Hyaluronic Acid is inflammatory and low molecular weight Hyaluronic Acid is controversial.
Some skin care experts advise using a Hyaluronic Acid that is small enough to penetrate the skin but not so deeply as to stimulate an immune system response. Others are more cautionary and recommend avoiding anything other than high molecular weight Hyaluronic Acid (HMW-HA).
But what represents the molecular size for the different classifications of Hyaluronic Acid? Despite extensive research on this, we were unable to find an industry standard to establish this or even find a common approach among manufacturers. Is 1000-1800kDa high molecular weight or medium molecular weight?
Disappointingly, many brands are spruiking that their products include low or ultra low molecular weight Hyaluronic Acid to gain a marketing edge, but without revealing what that molecular weight is. And this is adding to shopper confusion as references to molecular sizes are not being using consistently. This represents a failure in the regulatory system governing cosmetics and needs to be addressed, especially given the potential for harm.
In addition, you should consider the purity and safety of the Hyaluronic Acid being used. Hyaluronic Acid can be derived from animal, marine or plant sources, so look at the source of the Hyaluronic Acid and the reputation of the brand.
Another approach is to seek to stimulate the natural production of Hyaluronic Acid. Scientific research conducted for P&G Beauty demonstrated that the use of topical Niacinamide and Glucosamine can increase the body’s ability to synthesise its own Hyaluronic Acid.
Hyaluronic Acid must be applied in the right way to deliver its lauded benefits. Some people complain that Hyaluronic Acid serums make their skin feel dry and tight, and this is more common for anyone who has dry skin or lives in a dry environment. Concentrated Hyaluronic Acid can preferentially draw moisture from your skin rather than from the air when air humidity is low, thereby making the skin feel drier rather than the opposite.
By using the right Hyaluronic Acid and applying it correctly, you can enjoy its benefits. Hyaluronic Acid, like other humectants, work best paired with occlusive ingredients to prevent moisture loss. Be sure to apply a quality moisturiser after applying a Hyaluronic Acid serum.
Sodium Hyaluronate is the salt form of Hyaluronic Acid and is more chemically stable, so is often preferentially used in skin care products. It functions in the same way as Hyaluronic Acid when applied to the skin. Hydrolysed Sodium Hyaluronate, like Hydrolysed Hyaluronic Acid, involves chemically micronising the molecules for better penetration and therefore presents the same risks as other ultra low molecular weight forms.