What should you know about glycogen?

Glycogen is a polymer of glucose, meaning it is a high molecular weight molecule composed of several glucose units. Its chemical structure is detailed below. It is found in both animal cells, particularly in the liver and muscles, as well as in plant cells. Glycogen is essential for energy storage and release. In humans, it is used to regulate blood sugar levels, or the amount of glucose in the blood. When blood sugar levels are high, the liver absorbs the excess glucose and stores it in the form of glycogen.

When muscles require energy, such as during physical activity, the liver breaks down glycogen into glucose through the process of glycogenolysis. This metabolic pathway occurs in several stages and requires the involvement of various enzymes such as glycogen synthase. If glycogen becomes depleted, the liver then uses proteins, lactate, or glycerol to reform glucose through gluconeogenesis. The synthesis and breakdown of glycogen are closely regulated by hormones such as insulin and glucagon.

The glycogen used in cosmetics is most often of plant origin and is obtained by extraction from corn or wheat. These are rich in starch, a macromolecule with a chemical structure similar to that of glycogen. In the case of corn, for example, the grains are first mechanically crushed by a press to release the starch they contain. The extract is then subjected to centrifugations and filtrations, allowing the separation of the starch from the proteins and fibers of the plant.

Once isolated, the starch undergoes enzymatic reactions and is transformed into glycogen. Amylolytic enzymes such as amylase are typically used to hydrolyze the glycosidic bonds of the starch, which releases glucose molecules. These are then polymerized to form glycogen chains under the action of other enzymes such as glycogen synthase. Finally, the obtained glycogen is purified by filtration to remove impurities.

When applied topically, glycogen primarily provides hydration to the skin. Indeed, this hydrophilic molecule is capable of retaining water on the skin's surface to prevent it from evaporating. Glycogen thus strengthens the hydrolipidic film, playing a protective role, and limits water loss. It is particularly used to formulate care products for dry skin or for individuals wishing to prevent skin aging. Hydration is indeed one of the key factors for supple and plump skin.

In addition to its hydrating effects, glycogen could potentially reduce the appearance of established wrinkles. Indeed, a non-independent study conducted with four individuals recently showed that the twice-daily application of a cream containing 0.1% glycogen could reduce crow's feet wrinkles by an average of 42% and forehead wrinkles by an average of 54.9%. This study also involved 30 volunteers with age spots. The same protocol was followed and an improvement in pigmentation of an average of 30% was noted. However, as this was a non-independent study conducted with a relatively small number of people, caution should be exercised when considering the firming and brightening effects of glycogen.

Overall, the scientific literature indicates a lack of major risk associated with the cosmetic use of glycogen. Indeed, the inclusion of this active ingredient as a humectant in formulations does not result in redness, irritation, or other adverse events. Glycogen is also entirely suitable for sensitive skin and does not present any particular incompatibility. Furthermore, its concentration in cosmetic products is not subject to any restrictions.

However, even though glycogen is a gentle active ingredient, it is advisable to perform a tolerance test before using a cosmetic product for the first time to prevent the risk of allergies and side effects. To do this, apply a small amount of the product to the inside of your elbow, on your wrist, or behind your ear and wait 24 to 48 hours to observe any potential skin reaction. Furthermore, always make sure to follow the user instructions of cosmetic products.

For the benefits it brings to the skin, we have decided to incorporate glycogen into our SPF 30 facial cream for wrinkles and fine lines. This hybrid formula, containing 85% naturally derived ingredients, helps combat photoaging and supports the dermal collagen network, thus ensuring firmer and more resilient skin. Suitable for all skin types, it is particularly recommended for individuals showing early signs of aging, such as dehydration fine lines and expression wrinkles. In addition to glycogen, this face cream contains biomimetic collagen, which supports hydration and strengthens the skin's barrier function, thereby improving its density. It also includes low molecular weight hyaluronic acid, known for its moisturizing properties, as well as a carefully selected set of sunscreens for their safety for health and the environment.

For individuals showing more pronounced signs of aging, we recommend our day cream for multiple signs of aging SPF 50. Formulated with 80% ingredients of natural origin, this treatment targets photo-induced signs of aging—such as wrinkles, dark spots, and overall skin laxity—day after day. In addition to its high photoprotective potential, this cream stands out thanks to its peptide complex that complements the action of glycogen. The peptide fragments it contains (Pal-GHK and Pal-GQPR), known as matrikines, stimulate the synthesis of collagen and hyaluronic acid—two key components for maintaining skin firmness and elasticity. Moreover, Pal-GHK helps protect collagen from the damaging effects of UVA rays, which are primarily responsible for skin sagging, while Pal-GQPR helps reduce inflammation triggered by UVB exposure.

• HALPRIN K. M. & OHKAWARA A. & al. Glucose and glycogen metabolism in the human epidermis. The Journal of Investigative Dermatology (1966).

• MELTZER-MATS E. & al. Direct production of glucose from glycogen under microwave irradiation. Royal Society of Chemistry (2012).

• YATSUHASHI H. & others. Effects of Glycogen on Ceramide Production in Cultured Human Keratinocytes through Acid Sphingomyelinase Activation. Journal of Applied Glycoscience (2021).

• Supplier document.