Amino acid sugar and primary constituent of mucopolysaccharides and hyaluronic acid. As such, it can be considered a skin-identical ingredient. In large concentrations acetyl glucosamine can be effective for wound healing. There is research showing that chitosan (which is composed of acetyl glucosamine) can help wound healing in a complex physiological process (Sources: Cellular-Molecular-Life-Science, February 1997, pages 131–140; and Biomaterials, June 2001, pages 1667–1673). However, the amount used in those studies was significantly greater than the amount used in cosmetics.
In terms of exfoliation, the research that does exist was done by Proctor & Gamble and Estee Lauder, and both companies sell skin-care products with acetyl glucosamine (Sources: Journal of Cosmetic Science, July-August 2009, pages 423–428; and Journal of the American Academy of Dermatology, February 2007, Supplement 2, page AB169).
In terms of its anti-wrinkle action, there is no research demonstrating that wrinkles are related to wounds. Acetyl glucosamine also has research demonstrating its inhibitory effect on melanin production. Thus, it can be an important ingredient in skin lightening products, particularly when combined with niacinamide. Most of the research concerning acetyl glucosamine’s effect on hyperpigmentation is from Procter & Gamble, and their Olay brand uses acetyl glucosamine in many products. Still, the research is compelling and the protocols sound (Sources: British Journal of Dermatology, August 28, 2009, Epublication; Journal of Cosmetic Dermatology, December 2007, pages 232–238; March 2007, pages 20–26; and December 2006, pages 309–315).