Acetyl glucosamine is a skin-replenishing ingredient that functions to reduce signs of aging through several mechanisms.
Acetyl glucosamine, or N-acetyl glucosamine, is a monosaccharide derivative of glucose. Chemically, it is an amide between glucosamine (an amino sugar) and acetic acid. Acetyl glucosamine has many biological functions. For example, when acetyl glucosamine is combined with glucuronic acid, it forms hyaluronic acid. In humans, hyaluronic acid is the major component of the extracellular matrix and is extensively distributed in connective, epithelial, and neural tissues. It is most abundant in the skin, accounting for 50% of the body’s total content of hyaluronic acid. As a substrate to hyaluronic acid synthesis, acetyl glucosamine is able to replenish hyaluronic acid when levels become depleted.
Acetyl glucosamine functions as an anti-aging skin care ingredient based on its ability to replenish hyaluronic acid. Hyaluronic acid is a key molecule involved in maintaining skin hydration with the ability to hold up to 1,000 times its weight in water. Youthful skin retains its turgor, resilience, and pliability due to its rich supply of hyaluronic acid and high water content. According to the journal DermatoEndocrinology, the most dramatic histochemical change observed in aging skin is the marked disappearance of hyaluronic acid in the epidermis.
Hyaluronic acid is suggested to be a valuable ingredient in cosmetics, however, it does not penetrate the skin efficiently due to its high molecular weight. Therefore, since acetyl glucosamine is a building block of hyaluronic acid and it effectively penetrates through the skin, it is thought that this ingredient can replenish hyaluronic acid in aging skin. Ultimately, this increases the skin’s water content, resulting in a more smooth, plump complexion.
A study published in the Journal of Cosmetic Science evaluated the effect of acetyl glucosamine on water content in human skin. In vivo, the researchers observed that topical treatments with a formulation containing N-acetyl-glucosamine led to an increase in skin moisturization and a decrease in skin flakiness.
In addition to maintaining skin hydration, hyaluronic acid has also been proven to have a protective effect on collagen synthesis. Collagen is responsible for the resilience, strength, durability, elasticity, smoothness and plump appearance of healthy skin. Elevated levels of degraded collagen and reduced collagen synthesis are known to cause signs of skin aging. By replenishing hyaluronic acid, acetyl glucosamine indirectly helps to protect collagen synthesis. The result is stronger skin that is less susceptible to wrinkle formation.
Another way acetyl glucosamine can improve the appearance of aging skin is through exfoliation. This ingredient provides skin exfoliating properties similar to alpha and beta hydroxy acids without the irritation. The same study mentioned above hypothesized that amino sugars like acetyl glucosamine could modulate keratinocyte cellular adhesion and differentiation, leading to the normalization of stratum corneum exfoliation. This finding could be very beneficial for those with sensitive skin since exfoliation with acids can lead to side effects such as redness, irritation, and photosensitivity.
Lastly, acetyl glucosamine has been found to reduce the appearance of facial hyperpigmentation in an 8-week, double-blind clinical trial. This ingredient reduces the production of melanin, a pigment that gives skin its color, through several mechanisms.
It is involved in the up-regulation of epidermal turnover genes and antioxidant-related genes, as well as the down-regulation of the cytoskeleton genes involved in melanosome transport. These changes are believed to be associated with pigment reduction, leading to a brighter, more even complexion.
There is limited data available on the safety of acetyl glucosamine as used in cosmetics and personal care products. According to EWG’s Skin Deep Cosmetic Database, acetyl glucosamine is rated as a 1 on a scale of 1 to 10, with 1 being the lowest risk to health and 10 being the highest.
References: Wikipedia, “N-Acetylglucosamine”, Dermatoendocrinol. 2012 Jul 1; 4(3): 253–258, J Cosmet Sci. 2009 Jul-Aug;60(4):423-8, LotionCrafter, “N-Acetylglucosamine”, Drug Des Devel Ther. 2014; 8: 1923–1928, Mar Drugs. 2010; 8(9): 2493–2516.