Sardana and colleagues raise very important points to consider about the efficacy of tacrolimus in treating vitiligo. We agree that tacrolimus induces several effects at the molecular level that might enhance the repigmentation of vitiligo-affected skin. Unfortunately, in vitro studies do not always determine the full effect of a molecule applied to skin and are not sufficient to prove its efficacy. Nonetheless, several clinical studies have evaluated the potential of tacrolimus for treating vitiligo.
Passeron T, Ortonne J. Effect of Tacrolimus on Vitiligo in Absence of UV Radiation Exposure. Arch Dermatol. 2007;143(1):115-126. doi:10.1001/archderm.143.1.120-a