Estrogens And The Hair Follicle

The document from 2004 reviews the role of estrogens, particularly 17ß-estradiol (E2), in hair follicle cycling and hair growth, highlighting the complexity of estrogen signaling and its effects on hair biology. Estrogens are known to act as hair growth inhibitors in most species and are used to treat telogen effluvium. The review discusses the expression of estrogen receptors in the skin, their potential target genes, and their interaction with other hormones and factors. It also notes that estrogens improve skin quality and may influence wound healing. In terms of hair growth, E2 has been found to inhibit hair shaft elongation in females but stimulate it in males, and to decrease the telogen rate and prolong the anagen phase in human scalp skin. The document emphasizes that the exact mechanisms of estrogen's effects on hair follicles are not fully understood and that further research is needed, particularly regarding sex-dependent differences and the modulation of E2-responsive genes.