Treatment of melasma using tranexamic acid: what's known and what's next.

Tranexamic acid is a procoagulant agent that is approved by the US Food and Drug Administration for treatment of menorrhagia and to prevent hemorrhage in patients with hemophilia undergoing tooth extractions. Through its inhibitory effects on the plasminogen activation pathway, tranexamic acid also mitigates the UV radiation-induced pigmentation response. Systemic tranexamic acid has consistently been reported as an effective treatment of melasma, though its broad use may be limited by the risk for thromboembolism. Limited studies have investigated the efficacy of topical tranexamic acid, with or without the use of adjunctive therapies to increase uptake. This review summarizes the effects of tranexamic acid on the pathophysiology of melasma and the available evidence on the off-label treatment of melasma using systemic and topical tranexamic acid.