What is Hyaluronic Acid and What Can It Do For Your Skin?

What is Hyaluronic Acid?

In the world of skincare, there are a few ingredients considered to be ‘superstars’, due to the many important benefits they impart when incorporated into your skincare routine. One of these, which has become wildly popular in recent years, is hyaluronic acid. You’ve likely heard of this ingredient and the fact that it helps to promote skin hydration. But what actually is hyaluronic acid, how does it work, and why is it so important to include it into your skincare routine?

The first thing to know is that hyaluronic acid is a natural component of human tissue. It is most abundant in skin, but is also found in cartilage, connective tissue, the eyes, and pretty much any other part of the body you can think of. Hyaluronic acid is a large molecule that helps maintain the structural integrity of these important tissues and to keep them supple and hydrated. It also plays a critical role in wound healing, tissue regeneration, regulation of inflammation, and aging. In the skin, hyaluronic acid forms an essential component of the extracellular matrix (aka the ‘glue’ that helps our cells stick together). Because it is capable of binding over 1,000 times its weight in water—which would be like squeezing about 45 gallons of water in one tea cup, it helps to attract and retain moisture within the skin tissue. As we age, hyaluronic acid levels drop over time, particularly in the outermost layer of our skin, leading to a loss of elasticity, moisture, and fullness. 

Due to its water-attracting power, hyaluronic acid is also an incredibly powerful skincare ingredient. And the range of different sizes of hyaluronic molecules that are available means it can address the need for hydration from several angles. Large hyaluronic acid molecules (known as high-molecular weight hyaluronic acid) cannot penetrate through the outermost layers of our skin. However, they can form a thin, breathable protective barrier that prevents water loss and helps attract water to the skin surface. This promotes a smoother and more even appearance. High-molecular weight hyaluronic acid also has been shown to have anti-inflammatory properties and to promote healing.

Hyaluronic acid molecules can be broken into smaller pieces to form what is known as low-molecular weight hyaluronic acid. Unlike the larger molecules, these smaller forms can penetrate the outer layer of the skin and help to draw moisture into the skin. This provides a deeper level of hydration, creating a plumping effect and minimizing the appearance of fine lines and wrinkles. There is also evidence that low-molecular weight hyaluronic acid can turn on protective immune pathways and help to stimulate collagen production, providing an important anti-aging benefit. Importantly, clinical studies have found significant benefits associated with topical use of both low- and high- molecular weight hyaluronic acid, including decreased wrinkle depth and improved hydration. And because it is a skin-native ingredient, hyaluronic acid is non-irritating and safe for use in pregnancy and for all skin types.

At Ellis Day Skin Science, we have formulated our new Hydrating Phage Serum to contain a high concentration of both high- and low-molecular weight hyaluronic acid, providing you with all of the skin-hydrating and protective benefits associated with both forms of this powerful ingredient. And Ellis Day Hydrating Phage Serum also contains the same blend of active phages as our original Balancing Phage Serum. These microbes that naturally live on healthy skin target and kill the bacteria that cause blemishes, breakouts, and inflammation. 

So, if your skin has been feeling dehydrated during these winter months and/or because you’ve been wearing a mask for hours each day, try our new Hydrating Phage Serum for a boost of hydration, along with the skin-balancing power of our antibacterial phages.  

If you have any questions about hyaluronic acid or how phage-based skincare can help you achieve healthier, balanced skin, please email us at hello@ellisdayskinscience.com. We’re happy to help!


  1. Dicker KT, Gurski LA, Pradhan-Bhatt S, Witt RL, Farach-Carson MC, Jia X. Hyaluronan: a simple polysaccharide with diverse biological functions. Acta Biomater. 2014;10(4):1558-1570. doi:10.1016/j.actbio.2013.12.019
  2. Gariboldi S, Palazzo M, Zanobbio L, Selleri S, Sommariva M, Sfondrini L, Cavicchini S, Balsari A, Rumio C. Low molecular weight hyaluronic acid increases the self-defense of skin epithelium by induction of beta-defensin 2 via TLR2 and TLR4. J Immunol. 2008 Aug 1;181(3):2103-10. 
  3. Papakonstantinou E, Roth M, Karakiulakis G. Hyaluronic acid: A key molecule in skin aging. Dermatoendocrinol. 2012;4(3):253-258. 
  4. Pavicic T, Gauglitz GG, Lersch P, Schwach-Abdellaoui K, Malle B, Korting HC, Farwick M. Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment. J Drugs Dermatol. 2011 Sep;10(9):990-1000.


About Ellis Day Skin Science

We believe that modern skincare must be grounded in true microbiome science. We believe the answers are in the wild, natural world, which includes the surface of your skin. 

At Ellis Day Skin Science, we pioneer natural phage-based products that target and kill bad bacteria associated with inflammation, damage, and aging, and enable good bacteria to flourish. By doing so, we aim to balance your skin microbiome for optimal skin health.

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