Platelet-rich plasma (PRP) is an autologous blood product containing high concentrations of platelets in a small volume of plasma.

PRP may act at the dermal papilla cells to promote new hair growth, contribute to faster telogen–anagen transition, and increase hair density; good results should be expected with the use of PRP.

In androgenetic alopecia, a positive effect was demonstrated after injections of PRP (mainly after three treatments), showing an increase of hair density in most patients.

The results obtained with the use of PRP in alopecia areata are not so consistent.

PRP might work in some types of cicatricial alopecia, such as lichen planopillaris, central centrifugal cicatricial alopecia, and frontal fibrosing alopecia.