Is there any way to prevent melasma?

Sunlight causes the skin to make more pigment, which can darken existing melasma and cause new patches. Sun protection often involves wearing a wide-brimmed hat while outdoors, seeking shade, and applying a broad-spectrum sunscreen (SPF 30 or greater) throughout the day. Look for a sunscreen formula with zinc oxide and/or titanium dioxide and iron oxide to limit the effects of the sun’s rays on your skin.