Why we sub glycerin for hyaluronic acid. It's not why you think!
As a natural skin care customer are you a fan of hyaluronic acid? I have heard many reasons why my customers don't like hyaluronic acid. Ranging from: "Hyaluronic Acid is bad because its production involves rooster combs", or simply because it's "synthetic". While I do feel bad for those poor roosters subjected to science, I'm going to take a deeper dive at the real science behind hyaluronic acid, and the scientific reason why I do not formulate my products using this ingredient.
Hint: it's not what you think.
Hyaluronic acid and glycerin are both considered "humectants". You have probably heard the word "humectant" in relation to skin care before. The term usually implies that the product "grabs moisture". In the case of hyaluronic acid, marketing has taught viewers that by applying this molecule to your skin, it will attract moisture from the air making your skin appear more hydrated and visibly plump. While this isn't completely false, it also isn't completely true.
Humectants like hyaluronic acid and glycerin don't necessarily work as magnets that attract water... nor do they powerfully pull water to the skin from the atmosphere. How humectant molecules work is via hydrogen bonds. In order for a humectant to bind it has to bump into water. This can't be done from a long distance. For example: A humectant on your skins surface is not going to attract moisture from the sky on a rainy day. In order to bind, humectant molecules need to bump into the water that is already present in/on your skin.
The reason I prefer glycerin in our hydrating products like the Rose Water + Gardenia Cleanser is because glycerin molecules are a similar molecular size to water. In fact, the molecule is so small it can actually fit into aquaporins (water channels). Some research suggests that glycerin can replace water in your skin because it can travel through this membrane. Hyaluronic acid being a much larger molecule sits on the skins surface rather than absorbing.
With glycerin deep within the skin, you will not only experience skin hydration, but skin hydration that lasts for a longer period of time since it evaporates more slowly than water alone.
With that, I do not have a dislike for hyaluronic acid, I simply choose to formulate our products with a more effective, and long lasting hydrating ingredient.
Have questions or comments? Let me know your thoughts!