Sodium Hyaluronate

Sodium Hyaluronate: Sodium hyaluronate, a smaller molecule version of hyaluronic acid (HA), is a humectant naturally found in skin. Along with Glycerol and Trehalose it has the ability to hold water, making it an excellent hydrating ingredient.

Along with an improved breathing skin barrier function, Sodium hyaluronate and the other humectants in The Biology Serum optimise hydration. We use Sodium hyaluronate because it can usefully sit in the skin. We don’t use Hyaluronic Acid because it’s half as effective and it sits on the skin surface.

There’s a skincare industry marketing falsehood that Hyaluronic Acid can hold 1,000 times its molecular weight in water. This erroneous claim originates from a 1961 publication that was misread. In 1998 a review article said Hyaluronic Acid could hold 6,000 times its weight in water, but cited no evidence. Without checking, this this falsehood was repeated in prominent journals, such as in 2009, so it acquired a scientific (and media) legitimacy.

Finally, in 2023 Borchers et al compared Glycerol to Hyaluronic Acid and proved the hype wrong. At room temperature 1 gram of Hyaluronic Acid can bind with 0.36 grams of water - not 1,000 grams of water and certainly not 6,000 grams.

[Bibliography]

Ogston et al. [1961’”The partition of solutes between buffer solutions and solutions containing hyaluronic acid.” Biocheem J.

Sutherland et al. [1998] "Novel and established applications of microbial polysaccharides," Trends in Biotechnology.

Becker et al. [2009] “Final Report of the Safety Assessment of Hyaluronic Acid, Potassium Hyaluronate, and Sodium Hyaluronate.” International Journal of Toxicology

Borchers et al. [2023] The Fallacy of Hyaluronic Acid Binding a Thousand Times Its Weight In Water.” ChemRxiv