Anhydroxylitol is a low–molecular weight, water-soluble polyol produced by dehydrating xylitol. In cosmetics it serves primarily as a humectant and skin-conditioning agent, binding ambient and intra-formulation water to raise stratum corneum hydration and improve tactile softness. Beyond simple water binding, it is commonly used as one component of the well-known “XAX” sugar trio (xylitylglucoside + anhydroxylitol + xylitol), which has been shown to reinforce epidermal barrier homeostasis by optimizing water circulation (e.g., AQP3 expression) and supporting water reserves. In controlled studies with the XAX system, corneometry increases and TEWL reductions have been reported versus placebo over both acute and multi-week timeframes, supporting moisturization claims and “barrier support” positioning in leave-on skin care.

In hair care, anhydroxylitol functions as a hygroscopic conditioning aid that helps equilibrate moisture within the fiber. Supplier and market data for XAX indicate restoration of hair moisture at the cuticle level and improved feel in cleansing and leave-on systems, making it useful for smoothing, frizz management, and enhancing combability without heavy build-up. It is readily incorporated into aqueous phases, gels, serums, shampoos, and conditioners, and is compatible with typical surfactant systems and a wide range of pH found in cosmetic products. For brand owners, anhydroxylitol offers a science-forward way to substantiate hydrating, barrier-care, and gentle-tolerance claims while maintaining a short, biodegradable INCI profile.