Sodium Acetylated Hyaluronate
Also known as Acetylated hyaluronic acid sodium salt, Acetylated sodium hyaluronate, O-acetyl sodium hyaluronate
“CIR Expert Panel says: safe as used in cosmetics.”
Sodium Acetylated Hyaluronate (CAS 158254-23-0) is the acetyl ester of Sodium Hyaluronate, in which one or more hydroxyl groups of the hyaluronic acid backbone are acetylated. The 2023 CIR Expert Panel assessed all 7 hyaluronate cosmetic ingredients as a group, explicitly naming Sodium Acetylated Hyaluronate in the conclusion as safe in the present practices of use and concentration. Acetylation confers enhanced skin penetration (measured at ~100 µm depth vs ~50 µm for non-acetylated forms by Raman spectroscopy) and greater resistance to hyaluronidase-mediated degradation. A 2022 peer-reviewed clinical study (Meunier et al., PMID 34708918) demonstrated anti-wrinkle activity via inhibition of MMP-1/3/9 gene expression in fibroblasts and a 6% reduction in total wrinkle count at 6 hours post-application. No adverse effects were reported. The Panel noted no concentration limits or use conditions apply.
Humectant: retains moisture in the stratum corneum; wINCID function listed as Humectants
Enhanced skin penetration (~100 µm) compared to non-acetylated Sodium Hyaluronate (~50 µm), enabling deeper dermal hydration
Greater stability against enzymatic degradation: hyaluronidase degrades only ~7% of acetylated form vs ~92% of non-acetylated form
Anti-wrinkle activity demonstrated clinically: significant reduction in crow's feet and nasolabial wrinkles in 28-day and 2-month human studies
Inhibits MMP-1, MMP-3, MMP-9 gene expression in fibroblasts, protecting type I collagen from degradation
Named explicitly in the 2023 CIR group safety assessment as safe in cosmetics in present practices of use and concentration
- · The Panel noted insufficient data to assess safety of any hyaluronate ingredient applied via airbrush delivery systems due to potential respiratory exposure
- · Acetylation increases skin penetration depth relative to native Sodium Hyaluronate; the Panel determined this does not raise a safety concern at cosmetic use concentrations
The 2023 CIR Panel noted that when hyaluronate ingredients are derived from animal sources (rooster combs), biologically-derived impurities (nucleic acids, proteins, endotoxins) may be present; industry should use necessary procedures to limit infectious agents
CIR Safety Assessment of Hyaluronates as Used in Cosmetics (Final Report, July 7, 2023) — Sodium Acetylated Hyaluronate named directly in…
“The Expert Panel concluded that the 7 following hyaluronate ingredients are safe in cosmetics in the present practices of use and concentration described in the safety assessment: Hyaluronic Acid, Hydrolyzed Calcium Hyaluronate, Hydrolyzed Hyaluronic Acid, Hydrolyzed Sodium Hyaluronate, Potassium Hyaluronate, Sodium Acetylated Hyaluronate, Sodium Hyaluronate”— FR_Hyaluronates_062023.pdf, p. 13