Hexylresorcinol is a synthetic ingredient with a long history of use in foods and pharmaceuticals. It has local anesthetic and antiseptic properties, and also exhibits antioxidant activity. Recently, hexylresorcinol has been recognized for its benefits in skin care formulations. Studies have determined that hexylresorcinol functions as a skin lightening agent that can be used to control hyperpigmentation. Hyperpigmentation is a common, usually harmless condition in which patches of skin become darker in color than the normal surrounding skin. Hyperpigmentation can be causes by excessive UV exposure, inflammation, skin injuries, and some skin conditions such as acne.
Hexylresorcinol improves hyperpigmentation through inhibition of tyrosinase. Tyrosinase is a key enzyme involved in the synthesis of melanin, the pigment that gives skin color. By inhibiting tyrosinase, hexylresorcinol helps to reduce abnormal pigmentation associated with aging and exposure to UV light. Hexylresorcinol also stimulates antioxidant activity (i.e. glutathione, glutathione peroxidase, and glutathione reductase). Antioxidants limit oxidative damage caused by free radicals, the unstable molecules that contribute to the formation of premature wrinkles and fine lines on the skin. Due to these properties, hexylresorcinol is primarily used in skin-whitening and brightening products.