Retinoids in Hair Disorders

Abstract

Vitamin A has been shown to have an essential role in the differentiation, growth and regulation of the human hair cycle. The use of both systemic and topical retinoids is implicated in both the pathogenesis and treatment of various hair disorders. Of particular importance is the direct impact that retinoids have in the dynamic hair growth cycle. Retinoic acid has been shown to directly affect the anagen initiation phase of the hair cycle and direct the differentiation of embryonic and induced pluripotent stem cells into keratinocytes to produce normal hair follicles. Retinoids also have a critical role in the up- or down-regulation of protein pathways depending on their mode of transmission..