Sodium Hyaluronate in Skincare Products

Photo: June 2005, Vitals magazine, Gisele on cover: Inside, prominent NYC dermatologist Patricia Wexler says she always packs Skinceuticals Hydrating B5 Gel, a product containing a high concentration of sodium hyaluronate, when traveling.

One of my favorite skincare ingredients is sodium hyaluronate, which is one of the natural moisturizing factors (NMFs) found in the skin. Together with lipids, NMFs keep skin from losing water, maintaining skin’s young, smooth, non-flaky appearance. In fact, a 2000 study by Sakai et. al cited by Paula Begoun, “the Cosmetics Cop,” found that a decrease in the lipid and NMF content of the skin leads to surface roughness, flaking, fine lines, and a tight, uncomfortable feeling. Within the skin, biologically-formed NMFs are made of amino acids and their metabolites, and are found exclusively inside the cells of the uppermost layer of the skin (the stratum corneum). Natural NMFs maintain moisture in the skin, even under low humidity, and provide an optimal environment for enzymatic functions (Baumann).

In skincare products, natural moisturizing factors are able to draw water into the skin, reducing trans-epidermal water loss (TEWL), and creating a slight swelling of the skin that reduces the appearance of wrinkles. NMFs in skincare products also help to temporarily stabilize and maintain the complex intercellular-skin matrix, which is the “glue” that holds the skin together; this gives skin a smoother appearance (Begoun). Therefore, NMFs are often included in “anti-wrinkle” and “anti-aging” products, but they improve the appearance of the skin on a temporary basis more than they provide actual long-term correction of the skin, like retinoids. Despite their lack of long-term anti-aging benefits, NMFs may still be important for anti-aging prevention, as, according to Dr. Howard Murad, hydration of the skin with NMFs allows the skin to operate at optimum capacity, and provides a better defense against environmental assaults.

NMFs include glycerin, urea, alpha hydroxy acid, lactic acid, propylene glycol, and hyaluronic acid, which all prevent evaporation of products, increasing their shelf life. All of these NMFs are humectants, meaning that they are able to attract water from the atmosphere if atmospheric humidity is greater than 80 percent. However, when atmospheric humidity is low, NMFs may actually cause dryness, as they extract water from the deeper layers of the skin (Baumann). For this reason, NMFs work best when they are combined with occlusives like dimethicone or paraffin, as they are in most skincare formulations (Baumann). Sodium hyaluronate is a particularly effective humectant because it is effective in both high and low humidity conditions (In Cosmetics). In its protonated acidic form (called hyaluronic acid), the compound can bind water up to 1000 times its volume (Baumann). However, sodium hyaluronate, with similar water-binding abilities, is commonly used instead of hyaluronic acid in skincare products due to its greater chemical stability (Kewpie). A product with a particularly high concentration of sodium hyaluronate is Skinceuticals Hydrating B5 Gel ($58.00, Drugstore.com).

Therefore, sodium hyaluronate is an excellent ingredient for skincare products, as it effectively binds to water under both high and low humidity. This plumps the skin and temporarily gives the reduced appearance of wrinkles and fine lines, and provides a barrier of protection for the skin. In times when the weather is changing (October, anyone?), those who experience seasonal dry skin may benefit from adding a sodium hyaluronate-rich product, such as Skinceuticals Hydrating B5 Gel, to their skincare regimé. From personal experience, the product is light but hydrating to the skin, and highly recommended. Please feel free to leave additional comments about this product, ingredient, or any other natural moisturizing factors.