Oral tranexamic acid is listed as a hemostatic agent and has been approved for the treatment of menorragia in females. It’s off label use in the treatment of Melasma started after some reports from Japan in 1980 stating that it was useful in the management of Melasma.
Nowadays most doctors would agree that a daily dose of 500mg in 2 divided doses for
a duration of 3 months is the recommended regime . Although there are now studies which show safety up to a period of 6 months.
TA in the form of topical applications usually in combination with other agents like niacinamide and Kojic acid have also been used.
It has also been used intradermally as in a mesococktail. TA can be used alone or in combination with the other more conventional treatment modalities for Melasma. Hope this helps.