While vitamin C (derivatives), albutin, kojic acid, and ellagic acid are well-known ingredients used in whitening cosmetics in Japan, hydroquinone is the most common whitening agent in the United States.

It has such a strong whitening effect that it is called “skin bleaching agent.” It is highly effective in suppressing the action of tyrosinase enzyme, which produces melanin pigment. Because of its high efficacy, side effects such as redness and peeling of the skin may occur in rare cases during the treatment process, so a doctor’s diagnosis is required before use.