A New Era of 5α-Reductase Inhibitors for Androgenetic Alopecia

In addition to these therapies, a new oral drug dutasteride has been reported to be efficient for AGA in a large-scale (n=917) randomized controlled trial (RCT) [2]. This reagent is a 5α-reductase inhibitor similarly to finasteride. Importantly, dutasteride suppresses both type I and II 5α-reductases while finasteride significantly suppresses only type II. Therefore, dutasteride is referred as a “dual inhibitor”. In the RCT the effect for hair growth in AGA was compared between 0.5mg/day dutasteride and 1mg/day finasteride. As a result, dutasteride significantly increased hair count and width and hair photographic assessment compared with finasteride [2]. Additionally, dutasteride improved the global photography in Korean men with AGA recalcitrant to finasteride [3]. On the other hand, a meta-analysis study indicated no significant difference in efficacy for AGA between these two drugs [4]. Collectively, it is still controversial whether there is significant difference in clinical efficiency by dutasteride and finasteride.