What is ascorbyl glucoside? The manufacturer says: it is a beneficial skin care ingredient

What is ascorbyl glucoside? Ascorbyl glucoside has a structure in which the C2-hydroxyl group of L-ascorbic acid is masked with glucose. Once permeated through the skin, ascorbyl glucoside is broken down into L-ascorbic acid and glucose by the enzyme alpha-glucosidase. Because ascorbyl glucoside is broken down into L-ascorbic acid, it has the same functions as an L-ascorbic acid: exhibiting high antioxidant activity, acting as a coenzyme for enzymes involved in collagen synthesis (prolyl and lysyl hydroxylase), and inhibiting the synthesis of melanin.

So what are the benefits of using products with ascorbyl glucoside as opposed to the usual vitamin C found in skin care formulations (L-ascorbic acid)?

Ascorbyl glucoside has greater stability than L-ascorbic acid, which tends to break down in heat, light, in the presence of oxygen, and in certain pH levels (hence why your vitamin C cream turns dark yellow or brown after a few uses). According to the research, ascorbyl glucoside has excellent stability in heat, light, and in the presence of oxygen and metal ions when compared to other forms of vitamin C. This means, that ascorbyl glucoside lasts over twice as long as other forms of vitamin C, and thereby delivers the effects of vitamin C to the skin for a longer period of time.

Are there any possible detriments to ascorbyl glucoside?

One foreseeable detriment is the presence of more glucose in the skin. After alpha-glucosidase breaks, ascorbyl glucoside into L-ascorbic acid and glucose, does the glucose contribute to the formation of advanced glycation endproducts (which can age/harden collagen) via the Maillard pathway? Or does something else happen to the glucose? Based on current research, it is impossible to tell if ascorbyl glucoside contributes to the concentration of sugars that feed into the Maillard pathway in the skin.

The other foreseeable detriment is that ascorbyl glucoside’s concentration is not listed on the product, unlike some products with L-ascorbic acid, which state that they are 5%, 10%, or 15% L-ascorbic acid. One may argue that ascorbyl glucoside is more stable than L-ascorbic acid, so a higher concentration of L-ascorbic acid does not dictate higher potency than a lower concentration of ascorbyl glucoside. Still, there is hope for labeling with concentrations of ascorbyl glucoside in the future, with this study by Lin et. al. suggesting that high-performance liquid chromatography with on-line microdialysis sampling can be used to determine the concentration of ascorbyl glucoside in skin care formulations.

So,  is ascorbyl glucoside a beneficial skin care ingredient?

Based on current research by the manufacturer of ascorbyl glucoside, yes, ascorbyl glucoside does seem beneficial, due to the fact that it provides the benefits of vitamin C to the skin in a more stable (and hence longer-lasting) formulation. In the meantime, it would be interesting if researchers investigate the effects of more glucose from ascorbyl glucoside in the skin, as it could be detrimental. But, based on what is currently known, ascorbyl glucoside seems like an excellent way to get the benefits of vitamin C without having to worry as much about your product breaks down in the air, heat, or light.