Hello Hyaluronic Acid, Who Are You?


Hyaluronic acid has become a ubiquitous ingredient, appearing in lots of skin care due to the fact that it is lauded for its hydration benefits and it can come in various forms and go by quite a few names, such as low weight, high weight, mixed weights, and even sodium hyaluronate. Many of you may be unsure of what hyaluronic acid is and what differentiates one type from another and what the benefits are from one weight to another. While the science says yea, there are some that say…I’m not sure. The bottom line, as it always is, do what works for you. What matters most is that we can love the skin we are in. Now let’s dig into the science!

A common question is what is the difference between low and high molecular weight hyaluronic acids, and is one better than the other? Firstly we need to know what are hyaluronic acids?

Hyaluronic acid is a naturally occuring sugar within the dermis and other areas of the body where lubrication is needed, like your joints. It is one of the most hydrophilic substances in nature, meaning it loves to hold onto water so much that it can hold up to 1000 times its weight in water! [1] Due to this property, hyaluronic acid is an effective humectant and brings much needed hydration to the skin. 

Our skin is very effective at keeping “stuff” out, and making sure that active ingredients penetrate the skin is often a challenge for formulators. A molecule’s weight dictates how deep a molecule can penetrate into the skin. Low-molecular weight hyaluronic acid penetrates the deeper layers of the skin, and may even reach the layers where our own hyaluronic acid originates. Whereas high-molecular weight hyaluronic acid will not penetrate but rather sit on the surface of the skin. Penetrating the skin isn’t always the most important thing, considering that the hydrating effect appears predominantly on the surface anyways.[2]

So what exactly is the difference between these hyaluronic acids, and is one better than the other? Different molecular weights serve different purposes depending on what kind of product you are creating. Since high-molecular weights form a gel and leave a tacky feeling after application, low-molecular weights are better suited for serums and products with a thinner consistency. Due to the depth of penetration, neither is better than the other which is why you are more likely to see mid to high-molecular weight hyaluronic acids on the market.[3]

It’s important to remember that effective hydration is a team effort. And with that in mind I would recommend Étymologie’s Total Hydration Serum, as it is exactly that, a superhero team of humectants and botanical extracts to help hydrate, moisturize and plump the skin. This serum includes vegan and botanical forms of hyaluronic acid. Vegan, as it is a product of biotechnology, and botanical, in the form of Senna seed extract. The Senna plant forms a layer on the epidermis locking in water, and along with the high-molecular weight hyaluronic acids, attracts moisture from the environment to the skin. An important note however, is that the environment can also be the skin itself, so if humidity is very low these actives will pull water from deeper within the skin to the surface where it can evaporate, effectively dehydrating the skin. In order to negate this effect you can layer an occlusive agent on top, like a cream moisturizer or your favourite oil-based serum.

Lastly, it’s important to remember that cosmetics do not change the biology of your skin. Cosmetics only change the appearance of the skin by altering the hydration levels of the epidermis. So if you want continued skin care benefits, it is very important to keep a consistent daily skin care routine. Seeing as hyaluronic acid has a very short half-life of less than a day topically[4], if you do use a hyaluronic acid in your skin care such as the Total Hydration Serum, I recommend using it once in the morning and evening. It goes without saying, but I’ll say it anyway, if you have found the best regime that is working for you then please continue using it. Trust yourself, no one knows your skin better than you do!

By Jamie Stanton, B.Sc @Jamie_the_Chemist 


[1,4] “Hyaluronic Acid. How Hyaluronic Acid Benefits Joints, Eyes & Skin.” Hyalogic®, 8 Oct. 2020, https://hyalogic.com/hyaluronic-acid/. 

[2] Lambert, Bianca. “One Of These Hyaluronic Acid Serums Is $7, The Other Is $300. What’s The Difference?” HuffPost, HuffPost, 21 Jan. 2020, www.huffpost.com/entry/hyaluronic-acid-difference_l_5e138fdde4b0b2520d260b53.

[3] Papakonstantinou, Eleni, et al. “Hyaluronic Acid: A Key Molecule in Skin Aging.” Dermato-Endocrinology, vol. 4, no. 3, 2012, pp. 253–258., doi:10.4161/derm.21923.