Acetyl Glucosamine
Also known as Acetyl Glucosamine, N-Acetylglucosamine, N-Acetyl-D-Glucosamine, NAG, GlcNAc
“CIR Expert Panel says: safe as used in cosmetics.”
Acetyl Glucosamine (N-Acetylglucosamine; primary CAS 10036-64-3) is an aminomonosaccharide derived from glucose and a natural component of glycoproteins, proteoglycans, and glycosaminoglycans in skin. The CIR Expert Panel published a dedicated final safety assessment in July 2022 covering Acetyl Glucosamine and three related glucosamine ingredients, concluding all are safe in cosmetics when formulated to be non-irritating; use data indicate up to 5% in leave-on face and neck products. Clinical studies document efficacy for hyperpigmentation reduction (2% NAG, 8 weeks; 4% niacinamide + 2% NAG combination, 10 weeks) and improved skin texture on the neck and decolletage (8% NAG, 16 weeks) with good tolerability; one case of contact dermatitis was reported at 8%. A humectant study confirmed increased stratum corneum water content and reduced desquamation. Acetyl Glucosamine is non-mutagenic in Ames assay and non-carcinogenic in 104-week F344 rat feeding study.
Skin conditioning and humectant: increases stratum corneum water content and reduces flaking via modulation of keratinocyte adhesion/differentiation, functioning as a gentler alternative to alpha-hydroxy acids
Hyperpigmentation reduction: topical 2% NAG reduced facial hyperpigmentation appearance in 8-week split-face clinical trial; combination with 4% niacinamide produced more pronounced reduction in pigmented spot area in 10-week RCT
Anti-aging and skin texture improvement: 8% NAG neck cream produced significant improvement in texture, firmness, and pigmentation on neck and decolletage over 16 weeks with strong tolerability
Non-mutagenic and non-carcinogenic: non-mutagenic in Ames assay up to 5000 µg/plate; 104-week dietary study in F344 rats at up to 5% showed no carcinogenic potential
NMF-related skin component: naturally present in skin as a monomer of chitin-like glycoconjugates; endogenous presence supports good systemic tolerability profile
- · Mild cumulative irritation was observed at 2% in a 21-day cumulative patch irritation assay using an eye cream formulation; Panel required 'formulated to be non-irritating' qualifier (SQ) as a result
- · One subject (out of 45) in the 8% neck cream study experienced contact dermatitis on two occasions; no other adverse events were reported
- · CIR Panel noted insufficient human sensitization data at maximum use concentration of 5%; in vitro sensitization assays (DPRA, KeratinoSens, h-CLAT) were all negative at tested concentrations
Acetyl Glucosamine inhibits tyrosinase glycosylation and may reduce melanin synthesis — Panel noted this is considered a drug effect in the US; cosmetic formulators should avoid marketing framing that implies skin bleaching
CIR Final Report: Safety Assessment of Glucosamine Ingredients as Used in Cosmetics (June 2022) — covers Acetyl Glucosamine, Glucosamine,…
“Acetyl Glucosamine, Glucosamine, Glucosamine HCl, and Glucosamine Sulfate are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating.”— FR_Glucosamine_062022.pdf, p. 20