April 2017 in “Journal of Investigative Dermatology”
Early and late matrix progenitors in hair follicles create different cell layers, with early ones forming the companion layer and later ones forming the inner root sheath and hairshaft.
PP405 is anticipated as a future treatment for dormant hair follicles, but its effectiveness and safety are uncertain. Current treatments include oral minoxidil and microneedling, with some avoiding finasteride due to side effects.
Hair loss is linked to cellular physiology and the IGF-1 to TGF-B1 ratio, not just androgen sensitivity. The theory lacks evidence, while finasteride and minoxidil are effective treatments.
Androgenetic alopecia is caused by DHT affecting hair growth. Finasteride and minoxidil are used to manage hair loss by blocking DHT and promoting hair growth.
PP405 is ineffective for miniaturized, fibrosed hair follicles in androgenetic alopecia. AMP303 may activate hair follicle stem cells, but minoxidil and finasteride are still the main treatments.