Kligman's trio remains the gold standard treatment for melasma. It contain hydroquinone which is an effective anti-melanogenic compound but that has poor tolerance and numerous side-effects. Thiamidol has been proven to be at least as effective as hydroquinone and has a very good safety profile. The objective of this study is to compare the Kligman's trio to the same preparation in which hydroquinone is replaced by thiamidol.