Acetyl Glutamine

Acetyl glutamine is a skin-conditioning/humectant amino acid derivative typically used at low concentrations (about 0.1–2%) and is generally well tolerated in clinical and post-marketing experience. It is not a pH-dependent exfoliating active, not a known sensitizer, and lacks the irritancy profile seen with acids, retinoids, fragrances, or harsher preservatives. Rare reactions can occur in highly reactive or barrier-impaired eczema skin, but overall its intrinsic irritation potential is very low, supporting a 0.2 score. Safety Notes: In commercial skincare, acetyl glutamine is most often used as a low-level humectant/skin-conditioning amino-acid derivative in leave-on creams, serums, toners, and eye products, commonly appearing at trace-to-low levels around 0.01–0.1% when part of broader amino-acid/NMF complexes. Higher-strength consumer-available formulas (typically leave-on serums/ampoules and barrier-repair moisturizers marketed for hydration/soothing) have been observed using dedicated acetyl glutamine dosing in the ~1–5% range; above this becomes uncommon due to cost, solubility/formulation practicality, and diminishing returns. No specific EU/FDA cosmetic concentration limit is set for acetyl glutamine, so market use is mainly constrained by formulation/stability and sensorial considerations rather than regulation.