This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: Main objective To assess the effects of treatment to limit or reduce melasma and prevent recurrence. Secondary objectives To clarify as far as possible, the optimal regimen for preventing and treating melasma To see whether factors such as race, sex, geography, seasonal variation and skin colour affect treatment response To determine the incidence of adverse reactions and side effects with different therapies To identify the need for further studies.