How tacrolimus may work in hair loss treatment

Clin Exp Dermatol. 2009 Dec;34(8):e937-40.

Topical tacrolimus suppresses the expression of vascular endothelial growth factor and insulin-like growth factor-1 in late anagen.
Wang Y, et al

Abstract
Tacrolimus has shown promising results in the treatment of various dermatological diseases, including hair loss. ….. In this study, we investigated the effects of topical tacrolimus on anagen in the hair cycle and on the expression of vascular endothelial growth factor (VEGF) and insulin-like growth factor-1 (IGF-1) mRNAs in mouse skin. Topical tacrolimus 0.1% ointment was applied to one side of the skin of depilated C57BL/6 mice. snip.. No obvious difference in skin colour, hair cycling or histological features was found between the treated and untreated skin, but the levels of Vegf mRNA and Igf-1 mRNA were markedly decreased in the treated skin in late anagen, compared with those in untreated skin.