What does hydroquinone do to your skin?

Hydroquinone is a skin-lightening agent that reduces dark spots, hyperpigmentation, and melasma. It works by blocking the enzyme tyrosinase, which is needed to produce melanin (the pigment that gives skin its color). By slowing melanin production, hydroquinone helps fade discoloration and evens skin tone over time. But long-term or improper use can lead to skin irritation or bluish-gray skin discoloration.