What is Ascorbyl Glucoside and what is it used for?

Ascorbyl Glucoside, also known as ascorbyl glucoside, is a water-soluble derivative of vitamin C, obtained by linking ascorbic acid to a glucose molecule. This structural modification primarily aims to improve the stability of vitamin C, which is naturally sensitive to oxidation, light, and air. In cosmetics, this enhanced stability allows for better preservation of formulations and more convenient everyday use.

Once applied to the skin, Ascorbyl Glucoside is not active per se: it must be hydrolyzed by skin enzymes such as α-glucosidases to release free ascorbic acid gradually. Thanks to this gradual release, ascorbyl glucoside is generally better tolerated than pure vitamin C, especially on sensitive or reactive skin. However, this enzymatic conversion results in a gentler and often slower action compared to vitamin C pure.

Ascorbyl Glucoside is primarily used for its role in protecting the skin against oxidative stress. It thus helps the skin combat free radicals, unstable molecules that, by reacting with cellular components, can degrade them. Free radicals can notably impair the network of collagen and elastin of the extracellular matrix and accelerate skin laxity and the appearance of wrinkles. Regular use of antioxidants, such as ascorbyl glucoside, helps prevent this process.

A comparative study conducted on human skin explants evaluated cutaneous delivery, stability, and antioxidant efficacy of a formula containing 1.8% ascorbyl glucoside compared to another containing 15% ascorbic acid. The results show that ascorbyl glucoside is fully converted into ascorbic acid by the skin before crossing the skin barrier, while leaving an unmetabolized fraction in the tissues, thus forming a reservoir available for subsequent conversion. This kinetic profile suggests a sustained antioxidant action over time, rather than a transient activity peak.

Functionally, antioxidant efficacy was assessed using several oxidative stress markers, including malondialdehyde (MDA), superoxide dismutase (SOD), and catalase. Despite a higher absolute amount of ascorbic acid in the skin after direct application of ascorbic acid, both formulations demonstrated a equivalent antioxidant protection across all measured parameters. These results indicate that a lower concentration of Ascorbyl Glucoside can offer efficacy comparable to that of ascorbic acid, while benefiting from improved chemical stability.

Ascorbyl Glucoside is also being studied for its potential depigmenting effect. It acts by modulating tyrosinase activity, a key enzyme in melanin synthesis, which may contribute to a gradual decrease in hyperpigmentation and a more uniform skin tone. A clinical study conducted on 27 Japanese women presenting with solar lentigines evaluated the effect of an Ascorbyl Glucoside-arginine complex (AGAC) applied as a 28% lotion twice daily for 24 weeks on one side of the face, compared with a placebo on the other side. The results showed a significant reduction in pigmentation scores in the treated area compared with the placebo as early as 12 weeks, with even more pronounced effects at 24 weeks. However, the researchers did not disclose the numerical values.

This suggests that ascorbyl glucoside could be relevant for preventing and mitigating the signs of photoaging.

Note : Studies in vitro have also demonstrated that Ascorbyl Glucoside inhibits the activity of collagenase and elastase, two enzymes responsible, respectively, for the degradation of collagen and elastin. This mechanism of action, if confirmed in vivo, could also be valuable for combating signs of skin aging.

The safety of Ascorbyl Glucoside has recently been evaluated by the CIR (Expert Panel for Cosmetic Ingredient Safety), an independent panel of scientists specializing in toxicology and the assessment of cosmetic ingredients. This panel examines available data on skin effects, systemic toxicity, and chemical interactions to determine whether an ingredient can be considered safe for use in cosmetic products. After analyzing the available studies, the CIR concluded that Ascorbyl Glucoside is safe for cosmetic use, does not pose a risk of photosensitization, is non‐irritating to the skin, and is neither genotoxic nor carcinogenic.

For example, its irritation and sensitization potential was assessed via a test involving 51 volunteers. Occlusive patches containing a 10% Ascorbyl Glucoside solution were applied repeatedly over three weeks, followed by a treatment-free period and a challenge phase on a different skin area. Reactions were graded on a 0–4 scale. None of the participants exhibited any adverse effects, and no sensitization or contact allergy was observed after the repeated application of the product. Other patch tests conducted in separate studies reached the same conclusions.

However, as with any active ingredient, it is still recommended to conduct a test to ensure individual tolerance.

• DUPLAN H. & al. Ascorbic acid 2-glucoside: An ascorbic acid pro-drug with longer-term antioxidant efficacy in skin. International Journal of Cosmetic Science (2021).

• IMOKAWA G. & al. Treatment with ascorbyl glucoside–arginine complex ameliorates solar lentigos. International Journal of Molecular Sciences (2024).

• HELDRETH B. & al. Safety assessment of ascorbyl glucoside and sodium ascorbyl glucoside as used in cosmetics. International Journal of Toxicology (2024).

• HUANG Y.-C. & al. Incorporation of ascorbic acid-2-glucoside into ulvan microneedles to enhance its permeation for anti-aging and whitening treatment. International Journal of Biological Macromolecules (2025).