Androgen Actions on the Human Hair Follicle: Perspectives

The document reviewed the complex role of androgens in human hair growth, focusing on the 'androgen paradox' where androgens promote beard growth but cause hair loss in androgenetic alopecia (AGA). It detailed the involvement of enzymes, androgen receptors, and coactivators in the androgen sensitivity of hair follicles, and how androgens affect the production of growth mediators, with varying effects depending on the hair follicle location. The review also discussed the interaction between androgen and Wnt/β-catenin signaling pathways, the impact of DHT on keratinocyte proliferation and hair follicle stem cell differentiation, and the potential therapeutic targets for AGA, including AR coactivators/corepressors. It mentioned a phase 1 trial with a 'Hair Stimulating Complex' and a meta-analysis identifying AGA susceptibility loci, suggesting that multiple pathways are involved in AGA beyond androgens. The document concluded that the understanding of androgen regulation in hair growth and AGA is still developing.