Dermal Papilla

The dermal papilla is a cluster of specialized mesenchymal cells located at the base of each hair follicle that sits beneath the hair matrix. It acts as a signaling and nutrient hub, supplying blood, growth factors, and molecular cues that regulate the hair growth cycle, control hair shaft thickness, and guide follicle development and regeneration.

Alterations in dermal papilla size, cell number, or signaling are implicated in common hair disorders; for example, in androgenetic alopecia dermal papilla cells can shrink and contribute to follicle miniaturization and thinner hairs. Because the dermal papilla is central to hair production, many medical and experimental approaches aim to preserve or restore its function to improve hair growth and graft survival in surgical procedures.