Hexylresorcinol

Hexylresorcinol is a phenolic skin-brightening active (tyrosinase inhibitor) typically used around ~0.1–1% in leave-on products, where it can be effective but is not universally “non-irritating.” Clinical and post-market data suggest generally good tolerability, yet mild irritation (stinging/erythema) can occur in reactive or barrier-impaired skin due to its phenolic structure and active mechanism. Given real-world cumulative use with other actives (retinoids/acids) and higher-risk eczema populations, a mild irritancy score is the safer, clinically aligned call. Safety Notes: In commercial OTC skincare, hexylresorcinol is most commonly used as a leave-on brightening/spot-correcting active, with low-end inclusion around 0.05–0.1% in multi-active serums and moisturizers where it plays a supporting role. Higher-strength consumer products (typically targeted dark-spot serums and treatment creams) are commonly formulated at ~0.5% and can reach about 1.0% in specialized OTC formulations; above this level is uncommon due to solubility, sensory limits, and irritation risk. Rinse-off products generally sit toward the low end because of limited contact time, while leave-on treatments account for the upper end of the observed market range.