Embryology, Histology, and Physiology of the Hair Follicle

Scalp biopsies are crucial for diagnosing hair loss conditions like Diffuse Unpatterned Alopecia (DUPA) and retrograde hair loss, as treatments like finasteride and dutasteride may not be effective if other conditions are present. Combining PPAR-GAMMA agonists with retinoids could improve treatments for conditions like Lichen Planopilaris.

Microneedling should target depths of 0.5mm to 1.5mm for hair loss, with weekly sessions at 1mm recommended. Combining microneedling with Minoxidil is common for improved results.

Pelage is developing a topical hair follicle stem cell therapy, PP405, for non-scarring alopecias like androgenetic alopecia, with Phase III trials planned and a potential market launch by 2027. The treatment may not require continuous use after initial regrowth.

Microneedling depth should be customized based on hair type and scalp area, with many users finding 0.5-0.6mm effective for miniaturized hairs to avoid damage. Users report varying pain levels and results, with some preferring shorter needle lengths and others using longer ones like 1.75mm for scalp health and density improvement.