It is done in five to ten sessions at two to six week intervals. Brightening shows from the third, because the body needs time to process and clear the broken-down pigment. Using several wavelengths does not mean going hard in one pass, so the session count stays the same.

Pigment varies in depth and type, so one laser cannot cover it all. Firing lasers suited to shallow and deep pigment in sequence within a session reaches pigment one alone would leave behind, saving sessions. The time and cost per session go up in exchange.

Melasma can return under the influence of UV and hormones, because breaking the pigment down does not remove the cause that makes it. The realistic approach is to maintain with sun protection and topical medication while adding sessions periodically, with extra care in summer.