Anhydroxylitol

Anhydroxylitol is a sugar-derived humectant used in leave-on products (often within the Aquaxyl complex) at low percentages to support barrier hydration and reduce transepidermal water loss. Available clinical/patch-test experience with polyol humectants suggests a low irritation profile, with reactions being uncommon and typically limited to very reactive or severely compromised skin. Because it is not a low-pH active, fragrance, or high-risk preservative, the overall irritation potential is very gentle, though not fully inert. Safety Notes: In commercial moisturizers/serums, anhydroxylitol is most often used as part of the Aquaxyl-type humectant complex (with xylitol and xylitylglucoside), where it can appear at very low levels (~0.05–0.2%) when the total complex is used around 0.5–1%. Higher-strength OTC leave-on hydration products commonly push the total complex to ~3–5%, which corresponds to roughly ~1–3% anhydroxylitol depending on the blend ratio; rinse-off formats (cleansers) tend to sit at the low end due to short contact time. There is no specific EU/FDA maximum for anhydroxylitol as a cosmetic ingredient, so the practical upper bound is set by formula aesthetics, tackiness, and overall polyol load rather than regulation.